Mitsubishi EHST20C-VM2C, EHST20C-VM6C, EHST20C-YM9C, EHST20C-TM9C, EHST20C-VM2EC Service Manual

SERVICE MANUAL

CONTENTS

1. REFERENCE MANUAL

...................................

2

2. SAFETY PRECAUTION

...................................

3

3. SPECIFICATIONS

............................................

6

4. PART NAMES AND FUNCTIONS

..................

7

5. OUTLINES AND DIMENSIONS

.......................

8

6. WIRING DIAGRAM

........................................

10

7. FIELD WIRING

...............................................

17

8. WATER SYSTEM DIAGRAM

.........................

21

9. CONTROLS

...................................................

25

10. TROUBLESHOOTING

...................................

45

11. DISASSEMBLY PROCEDURE

......................

61

12. SUPPLEMENTARY INFORMATION

.............

84

13. SERVICE AND MAINTENANCE

...................

85

Note:

• This manual describes
only service data of cylin­der unit.

• RoHS compliant products
have <G> mark on the
spec name plate.

R410A

PARTS CATALOG (OCB570)

CYLINDER UNIT

December 2014

CYLINDER UNIT

No. OCH570

[Model name]

EHST20C-VM2C

EHST20C-VM6C

EHST20C-YM9C

EHST20C-TM9C

EHST20C-VM2EC

EHST20C-VM6EC

EHST20C-YM9EC

EHST20C-MHCW

EHST20C-MEC

EHST20D-VM2C

EHST20D-MHCW

EHST20D-MEC

EHST20D-MHC

EHPT20X-VM2C

EHPT20X-VM6C

EHPT20X-YM9C

EHPT20X-TM9C

EHPT20X-MHCW

[Service Ref.]

EHST20C-VM2C.UK
EHST20C-VM6C.UK
EHST20C-YM9C.UK
EHST20C-TM9C.UK
EHST20C-VM2EC.UK
EHST20C-VM6EC.UK
EHST20C-YM9EC.UK
EHST20C-MHCW.UK
EHST20C-MEC.UK
EHST20D-VM2C.UK
EHST20D-MHCW.UK
EHST20D-MEC.UK
EHST20D-MHC.UK
EHPT20X-VM2C.UK
EHPT20X-VM6C.UK
EHPT20X-YM9C.UK
EHPT20X-TM9C.UK
EHPT20X-MHCW.UK

MAIN REMOTE
CONTROLLER

2

REFERENCE MANUAL

1

OUTDOOR UNIT'S SERVICE MANUAL

Service Ref. Service Manual No.

PUHZ-W50/85VHA(-BS)

OCH439

PUHZ-W50/85VHAR1(-BS)

PUHZ-W50VHAR2(-BS)

PUHZ-W50VHAR3(-BS)

PUHZ-W85VHA2-BS.UK

OCH465

PUHZ-W85VHA2(R1)-BS.UK

PUHZ-W112VHA(-BS) OCH562

PUHZ-HW112/140YHA(-BS)

OCH439

PUHZ-HW112/140YHA2(-BS)

PUHZ-HW112/140YHA2R1(-BS)

PUHZ-HW112/140YHA2R3(-BS)

PUHZ-HW112/140YHA2R4(-BS)

PUHZ-HW140VHA(-BS)

PUHZ-HW140VHA2(-BS)

PUHZ-HW140VHA2R1(-BS)

PUHZ-HW140VHA2R2-BS

PUHZ-HW140VHA2R3(-BS)

PUHZ-HW140VHA2R4(-BS)

PUHZ-SW40/50VHA(-BS)

OCH525

PUHZ-SW40/50VHAR1(-BS)

PUHZ-SW75/100/120VHA(-BS)

OCH533PUHZ-SW100/120YHA(-BS)

PUHZ-SW100/120YHAR1(-BS)

PUHZ-SHW80/112VHA

OCH526

PUHZ-SHW80/112VHAR2(-BS).UK

PUHZ-SWH112/140YHA(R1)

PUHZ-SWH112/140YHAR2(-BS).UK

PUHZ-FRP71VHA OCH544

SUHZ-SW45VA(H).TH

OCH557

SUHZ-SW45VA(H)R1.TH

OCH570

3

SAFETY PRECAUTION

2

Please read the following safety precautions carefully.

WARNING:

Precautions that must be observed to prevent injuries or death.

CAUTION:

Precautions that must be observed to prevent damage to unit.

This installation manual along with the user manual should be left with the product after installation for future reference.
Mitsubishi Electric is not responsible for the failure of locally-supplied parts.

• Besuretoperformperiodicalmaintenance.

• Besuretofollowyourlocalregulations.

• Besuretofollowtheinstructionsprovidedinthismanual.

WARNING

Mechanical

The cylinder unit and outdoor unit must not be installed, disassembled, relocated, altered or repaired by the user. Ask an authorised installer or technician. If

the unit is installed improperly or modied after installation by the user water leakage, electric shock or re may result.

The outdoor unit should be securely xed to a hard level surface capable of bearing its weight.

The cylinder unit should be positioned on a hard level surface capable of supporting its lled weight to prevent excessive sound or vibration.

Do not position furniture or electrical appliances below the outdoor unit or cylinder unit.

The discharge pipework from the emergency devices of the cylinder unit should be installed according to local law.

Only use accessories and replacement parts authorised by Mitsubishi Electric ask a qualied technician to t the parts.

Electrical

All electrical work should be performed by a qualied technician according to local regulations and the instructions given in this manual.

The units must be powered by a dedicated power supply and the correct voltage and circuit breakers must be used.

Wiring should be in accordance with national wiring regulations. Connections must be made securely and without tension on the terminals.

Earth unit correctly.

General

Keep children and pets away from both the cylinder unit and outdoor unit.

Do not use the hot water produced by the heat pump directly for drinking or cooking. This could cause illness to the user.

Do not stand on the units.

Do not touch switches with wet hands.

Annual maintenance checks on both the cylinder unit and the outdoor unit should be conducted by a qualied person.

Do not place containers with liquids on top of the cylinder unit. If they leak or spill onto the cylinder unit damage to the unit and/or re could occur.

Do not place any heavy items on top of the cylinder unit.

When installing, relocating, or servicing the cylinder unit, use only the specied refrigerant (R410A) to charge the refrigerant lines. Do not mix it with any other
refrigerant and do not allow air to remain in the lines. If air is mixed with the refrigerant, then it can be the cause of abnormal high pressure in the refrigerant
line, and may result in an explosion and other hazards.
The use of any refrigerant other than that specied for the system will cause mechanical failure or system malfunction or unit breakdown. In the worst case, this
could lead to a serious impediment to securing product safety.

In heating mode, to avoid the heat emitters being damaged by excessively hot water, set the target ow temperature to a minimum of 2ºC below the maximum
allowable temperature of all the heat emitters. For Zone2, set the target ow temperature to a minimum of 5ºC below the maximum allowable ow temperature

of all the heat emitters in Zone2 circuit.

CAUTION

Use clean water that meets local quality standards on the primary circuit.

The outdoor unit should be installed in an area with sufcient airow according to the diagrams in the outdoor unit installation manual.

The cylinder unit should be located inside to minimise heat loss.

Water pipe-runs on the primary circuit between outdoor and indoor unit should be kept to a minimum to reduce heat loss.

Ensure condensate from outdoor unit is piped away from the base to avoid puddles of water.

Remove as much air as possible from the primary and DHW circuits.

Refrigerant leakage may cause suffocation. Provide ventilation in accordance with EN378-1.

Be sure to wrap insulation around the piping. Direct contact with the bare piping may result in burns or frostbite.

Never put batteries in your mouth for any reason to avoid accidental ingestion.

Battery ingestion may cause choking and/or poisoning.

Install the unit on a rigid structure to prevent excessive sound or vibration during operation.

Do not transport the cylinder unit with water inside the DHW tank. This could cause damage to the unit.

If power to the cylinder unit is to be turned off (or system switched off) for a long time, the water should be drained.

If unused for a long period, before operation is resumed, DHW tank should be ushed through with potable water.

Preventative measures should be taken against water hammer, such as installing a Water Hammer Arrestor on the primary water circuit, as directed by the man-

ufacturer.

As for the handling of refrigerant, refer to the outdoor unit installation manual.

OCH570

4

WARNING (SPLIT MODELS ONLY)

Do not discharge refrigerant into the atmosphere if refrigerant leaks during installation, ventilate the room.

Use appropriate tools for high pressure refrigerant.

When pumping down refrigerant , stop the compressor before disconnecting the refrigerant pipes.

During installation securely fasten the refrigerant pipes before starting the compressor.

Check that refrigerant gas does not leak after the completion of installation.

Use R410A refrigerant only. Do not allow air to enter the lines. Failure to observe these instructions will cause mechanical failure, system failure or, in the worst

case, serious breach of product safety.

CAUTION (SPLIT MODELS ONLY)

<Using R410A refrigerant heat pumps>

Use C1220 copper phosphorus, for copper and copper alloy seamless pipes, to connect the refrigerant pipes. Make sure the insides of the pipes are clean and
do not contain any harmful contaminants such as sulfuric compounds, oxidants, debris, or dust. Use pipes with the specied thickness. (Refer to section 4.4 in
the installation manual.) Note the following if reusing existing pipes that carried R22 refrigerant.

- Replace the existing are nuts and are the ared sections again.

- Do not use thin pipes. (Refer to section 4.4 in the installation manual.)

Store the pipes to be used during installation indoors and keep both ends of the pipes sealed until just before brazing. (Leave elbow joints, etc. in their packag­ing.) If dust, debris, or moisture enters the refrigerant lines, oil deterioration or compressor breakdown may result.

Use ester oil, ether oil, alkylbenzene oil (small amount) as the refrigeration oil applied to the ared sections. If mineral oil is mixed in the refrigeration oil, oil dete-

rioration may result.

Do not use refrigerant other than R410A refrigerant. If another refrigerant is used, the chlorine will cause the oil to deteriorate.

Use the following tools specically designed for use with R410A refrigerant. The following tools are necessary to use R410A refrigerant. Contact your nearest

dealer for any questions.

Tools (for R410A)

Gauge manifold Flare tool

Charge hose Size adjustment gauge

Gas leak detector Vacuum pump adapter

Torque wrench Electronic refrigerant charging scale

Be sure to use the correct tools. If dust, debris, or moisture enters the refrigerant lines, refrigeration oil deterioration may result.

Do not use a charging cylinder, a cylindrical measuring container, when charging R410A refrigerant gas. If the refrigerant gas is transferred to a charging cylinder,
the composition of the refrigerant will change and system efciency will be reduced.

OCH570

Gravimeter

Unit

5

[1] Cautions for service

(1) Perform service after recovering the refrigerant left in unit completely.
(2) Do not release refrigerant in the air.
(3) After completing service, charge the cycle with specified amount of refrigerant.
(4) When performing service, install a filter drier simultaneously.

Be sure to use a filter drier for new refrigerant.

[2] Additional refrigerant charge

When charging directly from refrigerant cylinder

· Check that cylinder for R410A on the market is syphon type.

· Charging should be performed with the

refrigerant

cylinder of syphon stood vertically. (Refrigerant is charged from liquid

phase.)

[3] Service tools

Use the service tools below as exclusive tools for R410A refrigerant.

No. Tool name Specifications

1

Gauge manifold

· Only for R410A

· Use the existing fitting

specifications

. (UNF1/2)

· Use high-tension side pressure of 5.3 MPa·G or over.

2

Charge hose

· Only for R410A

· Use pressure performance of 5.09 MPa·G or over.

3

Electronic scale

—

4

Gas leak detector · Use the detector for R134a, R407C or R410A

5

Adaptor for reverse flow check · Attach on vacuum pump.

6

Refrigerant charge base

—

7

Refrigerant cylinder

· Only for R410A ·Top of cylinder (Pink)

· Cylinder with syphon

8

Refrigerant recovery equipment

—

OCH570

6

SPECIFICATIONS

3

Model name

EHST20C-

VM2C

EHST20C-

VM6C

EHST20C-

YM9C

EHST20C-

TM9C

EHST20C-

VM2EC

EHST20C-

VM6EC

EHST20C-

YM9EC

EHST20C-

MEC

EHST20D-

VM2C

EHST20D-

MEC

EHST20D-

MHC

EHPT20X-

VM2C

EHPT20X-

VM6C

EHPT20X-

YM9C

EHPT20X-

TM9C

EHPT20X-

MHCW

EHST20C-

MHCW

EHST20D-

MHCW

Nominal domestic hot water volume 200L

Overall unit dimensions 1600 × 595 × 680 mm (Height × Width × Depth)

Weight (empty) 110 kg 111 kg 112 kg 112 kg 104 kg 105 kg 106 kg 103 kg 103 kg 96 kg 103 kg 98 kg 99 kg 100 kg 100 kg 98 kg 110 kg 103 kg

Weight (full) 320 kg 321 kg 322 kg 322 kg 314 kg 315 kg 316 kg 313 kg 312 kg 305 kg 312 kg 307 kg 308 kg 309 kg 309 kg 307 kg 320 kg 312 kg

Plate heat exchanger (MWA2)

— — — — — — — — —

Plate heat exchanger (MWA1) — — — — — — — —

— — — — — —

Unvented expansion

vessel(Primary heating)

Nominal volume 12 L — — -— — 12 L — 12 L

Charge pressure 1 bar — — — — 1 bar — 1 bar

Safety

device

Water

circuit

(Primary)

Control

thermistor

Heating 1 - 80°C

Pressure relief valve 0.3 MPa (3bar)

Flow sensor Min ow 5.0 L/min

Booster

heater

Manual reset thermostat 90°C — 90°C — — 90°C — — —

Thermal Cut-out (for dry run prevention) 121°C — 121°C — — 121°C — — —

DHW

tank

Control thermistor 40 - 70°C

Temperature and pressure relief valve/

Pressure relief valve

1.0 MPa

(10 bar)

1.0 MPa

(10 bar)

1.0 MPa

(10 bar)

1.0 MPa

(10 bar)

1.0 MPa

(10 bar)

1.0 MPa

(10 bar)

1.0 MPa

(10 bar)

1.0 MPa

(10 bar)

1.0 MPa

(10 bar)

1.0 MPa

(10 bar)

1.0 MPa

(10 bar)

1.0 MPa

(10 bar)

1.0 MPa

(10 bar)

1.0 MPa

(10 bar)

1.0 MPa

(10 bar)

90°C/

0.7 MPa

(7 bar)

90°C/

0.7 MPa

(7 bar)

90°C/

0.7 MPa

(7 bar)

Primary circuit circulating Pump Grundfos UPM2 15 70 - 130

Sanitary circuit circulating Pump Grundfos UPSO 15-60 130 CIL2

Connections

Water 28mm compression primary circuit/ 22mm compression DHW circuit

Refrigerant

(R410A)

Liquid 9.52 mm 9.52 mm 9.52 mm 9.52 mm 9.52 mm 9.52 mm 9.52 mm 9.52 mm 6.35 mm 6.35 mm 6.35 mm

— — — — —

9.52 mm 6.35 mm

Gas 15.88 mm 15.88 mm 15.88 mm 15.88 mm 15.88 mm 15.88 mm 15.88 mm 15.88 mm 12.7 mm 12.7 mm 12.7 mm 15.88 mm 12.7 mm

Target tempera-

ture range

Flow tem-

perature

Heating 25 - 60°C

Cooling —

Room tem-

perature

Heating 10 - 30 °C

Cooling —

Guaranteed

operating range

Ambient *1 0 - 35°C (

80 %RH)

Outdoor

temperature

Heating See outdoor unit spec table.

Cooling —

DHW tank

performance

Maximum allowable hot water temperature

70°C *4 70°C *4 70°C

Time to raise DHW tank temp 15 - 65 °C *2

22.75 mins

Time to reheat 70% of DHW tank to 65 °C *2

17.17 mins

Electrical data

Control

board

Power supply

(Phase, voltage, frequency)

~/N, 230 V, 50 Hz

Breaker (*when powered

from independent source)

10A

Booster

heater

Power supply

(Phase, voltage, frequency)

~/N, 230 V,

50 Hz

~/N, 230 V,

50 Hz

3~, 400 V,

50 Hz

3~, 230 V,

50 Hz

~/N, 230 V,

50 Hz

~/N, 230 V,

50 Hz

3~, 400 V,

50 Hz

—

~/N, 230 V,

50 Hz

— —

~/N, 230 V,

50 Hz

~/N, 230 V,

50 Hz

3~, 400 V,

50 Hz

3~, 230 V,

50 Hz

— — —

Capacity 2kW

2kW+

4kW

3kW+

6kW

3kW+

6kW

2kW

2kW+

4kW

3kW+

6kW

— 2kW — — 2kW

2kW+

4kW

3kW+

6kW

3kW+

6kW

—

— —

Current 9 A 26 A 13A 23A 9 A 26 A 13A — 9 A — — 9 A 26 A 13A 23A —

— —

Breaker 16 A 32 A 16A 32A 16 A 32 A 16A — 16 A — — 16 A 32 A 16A 32A —

— —

Immersion

heater*3

Power supply

(Phase, voltage, frequency)

—

~/N, 230 V,

50 Hz

—

~/N, 230 V,

50 Hz

Capacity — 3kW — 3kW

Current — 13A — 13A

Breaker — 16A — 16A

Sound level 28dBA

Optional extras

●

Wireless Remote Controller PAR-WT50R-E

●

Remote Sensor PAC-SE41TS-E *1 The environment must be frost-free.

●

Wireless Receiver PAR-WR51R-E

●

Thermistor PAC-TH011-E *2 Tested under BS7206 conditions.

●

Immersion heater (1Ph 3kW) PAC-IH03V2-E

●

High temperature thermistor PAC-TH011HT-E *3 Do not t immersion heaters without thermal cut-out.

●

EHPT Accessories for UK PAC-WK01UK-E

●

ecodan Wi-Fi Interface PAC-WF010-E *4 For the model without both booster heater and immersion heater, the maximum allowable hot water temperature is [Maximum outlet water of outdoor unit - 3°C]

For the maximum outlet water of outdoor unit, refer to outdoor unit data book.

OCH570

7

PART NAMES AND FUNCTIONS

4

21

B

A

<EH*T20*-MHCW>
(UK split / packaged model system)

7

4

12

<EHPT20X-*M**C*>
(Packaged model system)

<EHST20*-*M**C*>

(Split model system)

<EHST20*-*M**C>
(Split model system)

<Note>

For installation of EHST20*-*M*EC
model, make sure to install a primary ­side expansion vessel in the field. (See
figure 4.3.1 in the installation manual.)

No. Part name

EHST20C-

VM2C

EHST20C-

*M6/9 C

EHST20C-

*M*EC

EHST20*-

MEC

EHST20D-

VM2C

EHST20D-

MHC

EHPT20X-

VM2C

EHPT20X-

*M6/9 C

EHPT20X-

MHCW

EHST20*-

MHCW

A DHW outlet pipe

B Cold water inlet pipe

C Water pipe (Space heating return connection)

D Water pipe (Space heating ow connection)

E Water pipe (Flow from heat pump connection) — — — — — — —

F Water pipe (Return to heat pump connection) — — — — — —

—

G Refrigerant pipe (Gas)

— — —

H Refrigerant pipe (Liquid) — — —

1 Control and electrical box

2 Main controller

3 Plate heat exchanger (Refrigerant - Water) — — —

4 Booster heater 1,2 — — — —

5 3-way valve

6 Manual air vent

7 Drain cock (Primary circuit)

8 Manometer

9 Pressure relief valve (3bar)

10 Automatic air vent

11 Expansion vessel — —

12 Flow sensor

13 Strainer valve

14 Water circulation pump 1 (Primary circuit)

15 Pump valve

16 DHW tank

17 Plate heat exchanger (Water - Water)

18 Scale trap

19 Water circulation pump (Sanitary circuit)

20 Immersion heater — — — — — — —

21 Temperature and pressure relief valve — — — — — — — —

22 Pressure relief valve (10bar) (DHW Tank) — —

23 Drain cock (DHW tank)

24 Drain cock (Sanitary circuit)

25 Flow water temp. thermistor (THW1)

26 Return water temp. thermistor (THW2)

27 DHW tank water temp. thermistor (THW5)

28 Refrigerant liquid temp. thermistor (TH2) — — —

29 Outdoor unit — — — — — — — — — —

30 Drain pipe (Local supply) — — — — — — — — — —

31 Back ow prevention device (Local supply) — — — — — — — — — —

32 Isolating valve (Local supply) — — — — — — — — — —

33 Magnetic lter (Local supply) (Recommended) — — — — — — — — — —

34 Strainer (Local supply) — — — — — — — — — —

35 Inlet control group *1 — — — — — — — — — —

36

Filling loop (Ball valves, check valves and exible hose) *1

— — — — — — — — — —

37 Potable expansion vessel *1 — — — — — — — — — —

*1 Supplied with UK model ONLY. Please refer to PAC-WK01UK-E Installation Manual for more information on accessories.

<EH*T20*-MHCW>
(UK split/packaged model system)

<EHPT20X-*M**C*>
(Packaged model system)

22

A

B

10

9

11

1

5

6

19

18

12

20

23
17

24

7

15

D

8
2

16

4

13

3

14

C

E/H

F/G

<Table 4-1>

<Figure 4-1>

OCH570

8

OUTLINES AND DIMENSIONS

5

<Unit: mm>

J

A

C
D

B

F/G

E/H

470.7

510.7

0

67.8

522.3

462.3

402.3

342.3

88.3

0

46.7

136.7

114.2

91.7

69.2

0

42.1

552.7

470.7

0

G1/2

83 427

30413

118

680

CPF 15mm

595

100 ± 20

449

1600

595

1600

449

J

A

B

D

C

F/G

E/H

46.7

136.7

114.2

91.7

69.2

0

67.8

522.3

462.3

402.3

342.3

127.8

0

552.7

542

0

470.7

510.7

0

680

100 ± 20

120 ± 20

G1/2

G1/2

118

123

Letter Pipe description Connection size/type

A DHW outlet connection 22 mm/Compression
B Cold water inlet connection 22 mm/Compression
C Space heating return connection 28 mm/Compression
D Space heating ow connection 28 mm/Compression
E Flow from heat pump connection (No plate heat exchanger) 28 mm/Compression
F Return to heat pump connection (No plate heat exchanger) 28 mm/Compression

G

Refrigerant (GAS)
(With plate heat exchanger)

12.7 mm/Flare (EHST20D-*)

15.88 mm/Flare (EHST20C-*)

H

Refrigerant (LIQUID)
(With plate heat exchanger)

6.35 mm/Flare (EHST20D-*)

9.52 mm/Flare (EHST20C-*)

J

Electrical cable inlets

For inlets , and , run low-voltage wires including external input wires and ther-

mistor wires. For inlets

and , run high-voltage wires including power cable, indoor-

outdoor cable, and external output wires.

*For a wireless receiver (option) cable and ecodan Wi-Fi interface (option) cable, use inlet .

<Left side> <Front> <Right side>

<Top>

Air vent

Main controller

Pressure relief valve
(Primary circuit)

Terminal block

Front panel

Temperature and
pressure relief valve
and it's access plate

<EH*T20*-*M**C>

<EH*T20*-MHCW>

Pressure relief valve
(Sanitary circuit)

Pressure relief valve
(Primary circuit)

Main controller

Terminal block

<Left side> <Front>

<Right side>

<Top>

Air vent

Front panel

5-1. Technical Drawings

OCH570

9

a

b b

d

Service access

5-2. Service access diagrams

Service access

Parameter Dimension (mm)
a 300
b 150
c

(distance behind unit not visible

in the right gure)

10

d 500

Sufcient space MUST be left for the provision of discharge pipework as detailed
in National and Local Building Regulations.

The cylinder unit must be located indoors and in a frost-free environment, for

example in a utility room, to minimise heat loss from stored water.

OCH570

1

3

5

7

X6

X7

1

3

1

3

CNBHT

(BLK)
CNBC
(GRY)

CNBH
(WHT)

NL

S3S2S1

NL

S3S2S1

To outdoor

unit

TB1

ORN

ORN

YLW

YLW

GRN/YLW

To outdoor

unit

Power supply
~/N 230V 50Hz

TB1

ORN

BLU

RED

BLU

RED

YLW

GRN/YLW

1

3

CN3C
(BLU)

BLK

BLK

BLK

BLK

1

3

ORN

BRN

CN3C
(BLU)

ORN

ORN

BRN

YLW

Indoor unit powered

by independent source

Indoor unit powered

via outdoor unit

CIRCUIT

BREAKER

1

3

CN3C
(BLU)

1

3

CNPWM

(WHT)

LED1

LED2

LED3

LED4

TBI.1

TBI.2

1310 12 141174 65 932 811310 12 141174 65 932 811310 12 141174 65 932 81

IN6

IN1

IN2

IN3

IN4

IN5

IN7

THW8

THW7

THW6

THW9

THWB1

THWB2

t°t°t°t°t°t

°

Main

controller

1

+

-+-+-

2

1

2

CN20

(RED)

TH1

t

°

1

3

CN21

(YLW)

TH2

t

°

1

4

THW1

THW2

CNW12

(RED)

t°t

°

1

2

THW5

CNW5

(WHT)

t

°

CN108

5

1

Wireless receiver

(Option)

WiFi adapter

(Option)

5

1

5

1

CNRF
(WHT)

CN105
(RED)

CN22
(BLU)

1

5

Close

Open

N

X15

X12

TBO.3

TBO.2

TBO.1

F1

F2

MXV

M

1

~

MP2

MP1

M

1

~

CNV1
(WHT)

X11

X10

X4

X14

X3

X2

X1

X5B

X5A

1
2
3
4
5
6
7
8

1
2
3
4
5
6

1
2
3
4
5
6

1

1

3

3

3

CNP1
(WHT)

CNP4
(RED)

CNPWM

(WHT)

TBO.1

TBO.2

TBO.3

TBO.4

CNP1

(WHT)

CNP4

(RED)

CNV1

(WHT)

CN22
(BLU)

CNIT
(BLU)

TAB1

CN01
(WHT)

F2 F1

6.3A 250V 10A 250V

SW1

SW2

SW3

SW4

SW5

1

8

1

8

1

1

5

1
3

1
3

8

1

8

1

6

CN01
(WHT)

CN01
(WHT)

2

1

4
6

2

1

1
2
4
6

4
6

CNBH
(WHT)

CNBC
(GRY)

1

1

3

1
2

1
2

1
2

CNBHT

(BLK)

1

3

7

1

3

CNIH

(ORN)

1

4

1

3

CNW5
(WHT)

CN21
(YLW)

CNW12

(RED)

CN20
(RED)

TBI.2

MP3

M

1

~

IN8

IN9

IN10

TBI.3

TBI.3

1

4

CN1A
(WHT)

TBI.1

2WV2b

M

1

~

M

1

~

MP4

M

1

~

1

3

L
(1)N(3)

ORN

RED

BLU

BLU

RED

ORN

IHC

IHT

IH

642

531

A1

A2

A B

2

4

Immersion heater (1Ph3kW)(Option)

Power supply

to Immersion heater

~/N 230V 50Hz

1

2

CNIH
(ORN)

3

3WV

M

1

~

Signal output

(Boiler)

Signal output

(Error)

Signal output

(Defrost)

Signal output

(Comp ON)

ECB2

1

2
4

6

CN01
(WHT)

WHT

WHT

2 2

2

ECB1

L

(1)N(3)

BHCP

BLU

BLU

RED

WHT/No.2

WHT/No.1

RED

VLT

VLT

GRY

GRY

BHC1

BHT

642

531

A1

A2

BH1

BHF

2

4

Power supply

to Booster heater

642

531

A1

A2

CNBH
(WHT)

CNBHT
(BLK)

2

2

2

CNBC
(GRY)

1

1

3

3

1

3

~/N 230V 50Hz

1
2
3
4
5
6

TBO.4

M

2WV2a

1

3

X9

X8

X13

CNIH

(ORN)

1
2
3
4
5
6

1
2
3
4
5
6

1
2
3
4
5
6
7
8

1
2
3
4
5
6

12 146 108

137 11945321

12 146 108

137 11945321

12 146 108

137 11945321

Tool

Tool

Conductor

Conductor

Outline view Top view

<How to use TBO.1 to 4>

Connect them using either way as shown below.

10

6 WIRING DIAGRAM

1. Symbols used in wiring diagram are, : connector, : terminal
block.

2. Indoor unit and outdoor unit connecting wires have polarities, make sure
to match terminal numbers (S1, S2, S3) for correct wirings,

3. Since the outdoor unit side electric wiring may change, be sure to check
the outdoor unit electric wiring diagram for service.

Table 1 Signal Inputs

Name

Terminal block

Connector

Item OFF (Open) ON (Short)
IN1 TBI.1 13-14 — Room thermostat 1 input Refer to SW2-1 in <6-7. DIP switch setting>.
IN2 TBI.1 11-12 — Flow switch 1 input Refer to SW2-2 in <6-7. DIP switch setting>.
IN3 TBI.1 9-10 — Flow switch 2 input (Zone1) Refer to SW3-2 in <6-7. DIP switch setting>.
IN4 TBI.1 7-8 — Demand control input Normal

Heat source OFF/ Boiler operation *2

IN5 TBI.1 5-6 —

Outdoor thermostat input *1

Standard operation

Heater operation/ Boiler operation *2
IN6 TBI.1 3-4 — Room thermostat 2 input Refer to SW3-1 in <6-7. DIP switch setting>.
IN7 TBI.1 1-2 — Flow switch 3 input (Zone2) Refer to SW3-3 in <6-7. DIP switch setting>.
IN8 TBI.3 1-2 — Electric energy meter 1

Refer to <6-7. DIP switch setting>.IN9 TBI.3 3-4 — Electric energy meter 2

IN10

TBI.3 5-6 — Heat meter

*1. If using outdoor thermostat for controlling operation of heaters, the lifetime of the heaters and related

parts may be reduced.

*2. To turn on the boiler operation, use the main controller to select “Boiler” in “External input setting“ screen

in the service menu.

Table 2 Outputs

Name

Terminal block

Connector

Item OFF ON

OUT1

TBO.1 1-2 CNP1 Water circulation pump 1 output (Space heating & DHW) OFF ON

OUT2

TBO.1 3-4 — Water circulation pump 2 output (Space heating for Zone1) OFF ON

OUT3

TBO.1 5-6 —

Water circulation pump 3 output (Space heating for Zone2)

*1

OFF ON

2-way valve 2b output *2

OUT4

TBO.2 4-6 CNV1 3-way valve output Heating DHW

OUT5

TBO.2 1-2

— Mixing valve output *1 Stop

Close

TBO.2 2-3 Open

OUT6

—

CNBH 1-3

Booster heater 1 output OFF ON

OUT7

—

CNBH 5-7

Booster heater 2 output OFF ON

OUT9

TBO.4 3-4 CNIH Immersion heater output OFF ON

OUT10

TBO.3 1-2 — Boiler output OFF ON

OUT11

TBO.3 3-4 — Error output Normal Error

OUT12

TBO.3 5-6 — Defrost output Normal Defrost

OUT13

TBO.4 1-2 — 2-way valve 2a output *2 OFF ON

OUT14

— CNP4 Water circulation pump 4 output (DHW) OFF ON

OUT15

TBO.3 7-8 — Comp ON signal OFF ON

Do not connect to the terminals that are indicated as “—” in the “Terminal block” eld.
*1. For 2-zone temperature control.
*2. For 2-zone valve ON/OFF control.

6-1. EHST20C-VM2C, EHST20C-VM2EC, EHST20D-VM2C, EHPT20X-VM2C

Symbol Name
TB1 Terminal block <Power supply, Outdoor unit>
ECB1

Earth leakage circuit breaker for booster heater

ECB2

Earth leakage circuit breaker for immersion heater

MP1

Water circulation pump 1(Space heating & DHW)

MP2

Water circulation pump 2 (Space heating for Zone1)(Local supply)

MP3

Water circulation pump 3 (Space heating for Zone2)(Local supply)

MP4 Water circulation pump 4 (DHW)
3WV 3-way valve
2WV2a 2-way valve (For Zone 1)(Local supply)
2WV2b 2-way valve (For Zone 2)(Local supply)
MXV Mixing valve (Local supply)
BHT Thermostat for booster heater
BHF Thermal fuse for booster heater
BH1 Booster heater 1
BHC1 Contactor for booster heater 1
BHCP Contactor for booster heater protection
IHT Thermostat (xed temp.) for immersion heater
IH Immersion heater
IHC Contactor for immersion heater

Symbol Name
TH1 Thermistor (Room temp.)(Option)
TH2 Thermistor (Ref. liquid temp.)
THW1 Thermistor (Flow water temp.)
THW2 Thermistor (Return water temp.)
THW5 Thermistor (DHW tank water temp.)
THW6 Thermistor (Zone1 ow temp.)(Option)
THW7 Thermistor (Zone1 return temp.)(Option)
THW8 Thermistor (Zone2 ow temp.)(Option)
THW9 Thermistor (Zone2 return temp.)(Option)
THWB1 Thermistor (Boiler ow temp.)(Option)
THWB2 Thermistor (Boiler return temp.)(Option)
IN1 Room thermostat 1 (Local supply)
IN2 Flow switch 1 (Local supply)
IN3 Flow switch 2 (Local supply)
IN4 Demand control (Local supply)
IN5 Outdoor thermostat (Local supply)
IN6 Room thermostat 2 (Local supply)
IN7 Flow switch 3 (Local supply)
IN8 Electric energy meter 1 (Local supply)
IN9 Electric energy meter 2 (Local supply)
IN10 Heat meter (Local supply)
FLOW TEMP. CONTROLLER (FTC5)

TBO.1-4

Terminal block <Outputs>
TBI.1-3 Terminal block <Signal Inputs, Thermistor>
F1 Fuse (T10AL250V)
F2 Fuse (T6.3AL250V)
SW1-5 DIP switch *See 6-7. DIP switch setting.
X1-15 Relay
LED1 Power supply (FTC5)
LED2 Power supply (Main controller)
LED3 Communication (FTC5-Outdoor unit)
LED4 Reading or writing data to SD card
CNPWM

Pump speed control signal for MP1

CN108 SD card connector

OCH570

WHT

WHT

2 2 2

2

ECB1

L

(1)N(3)

BHCP

BLU

BLU

BLU

REDRED

BLU/No.3

WHT/No.2

WHT/No.1

BLU/No.4

RED

VLT

VLT

PNK

PNK

GRY

GRY

BHC2

BHC1

BHT

642

531

A1

A2

642

531

A1

A2

BH1

BHF

BH2

2

4

Power supply

to Booster heater

642

531

A1

A2

CNBH

(WHT)

CNBHT

(BLK)

2

2

2

2

CNBC
(GRY)

1

1

3

5

7

3

1

3

~/N 230V 50Hz

1

3

5

7

X6

X7

1

3

1

3

CNBHT

(BLK)
CNBC
(GRY)

CNBH
(WHT)

NL

S3S2S1

NL

S3S2S1

To outdoor

unit

TB1

ORN

ORN

YLW

YLW

GRN/YLW

To outdoor

unit

Power supply

~/N 230V 50Hz

TB1

ORN

BLU

RED

BLU

RED

YLW

GRN/YLW

1

3

CN3C
(BLU)

BLK

BLK

BLK

BLK

1

3

ORN

BRN

CN3C
(BLU)

ORN

ORN

BRN

YLW

Indoor unit powered

by independent source

Indoor unit powered

via outdoor unit

CIRCUIT

BREAKER

1

3

CN3C
(BLU)

1

3

CNPWM

(WHT)

LED1

LED2

LED3

LED4

TBI.1

TBI.2

1310 12 141174 65 932 811310 12 141174 65 932 811310 12 141174 65 932 81

IN6

IN1

IN2

IN3

IN4

IN5

IN7

THW8

THW7

THW6

THW9

THWB1

THWB2

t°t°t°t°t°t

°

Main

controller

1

+

-+-+-

2

1

2

CN20

(RED)

TH1

t

°

1

3

CN21

(YLW)

TH2

t

°

1

4

THW1

THW2

CNW12

(RED)

t°t

°

1

2

THW5

CNW5

(WHT)

t

°

CN108

5

1

Wireless receiver

(Option)

WiFi adapter

(Option)

5

1

5

1

CNRF
(WHT)

CN105
(RED)

CN22
(BLU)

1
2
3
4
5
6

1

5

Close

Open

N

TBO.4

TBO.2

TBO.1

F1

F2

M

2WV2a

MXV

M

1

~

MP2

MP1

M

1

~

1

3

CNV1
(WHT)

X9

X8

X13

X4

X14

X3

X2

X1

X5B

X5A
1
2
3
4
5
6

1
2
3
4
5
6

1

1

3

3

3

CNP1
(WHT)

CNP4
(RED)

CNPWM

(WHT)

TBO.1

TBO.2

TBO.3

TBO.4

CNP1
(WHT)

CNP4
(RED)

CNV1
(WHT)

CN22
(BLU)

CNIT
(BLU)

TAB1

CN01
(WHT)

F2 F1

6.3A 250V 10A 250V

SW1

SW2

SW3

SW4

SW5

1

8

1

8

1

1

5

1
3

1
3

8

1

8

1

6

CN01
(WHT)

CN01
(WHT)

2

1

4
6

2

1

1
2
4
6

4
6

CNBH
(WHT)

CNBC
(GRY)

1

1

3

1
2

1
2

1
2

CNBHT

(BLK)

1

3

7

1

3

CNIH

(ORN)

1

4

1

3

CNW5
(WHT)

CN21
(YLW)

CNW12

(RED)

CN20

(RED)

TBI.2

CNIH
(ORN)

MP3

M

1

~

IN8

IN9

IN10

TBI.3

TBI.3

1

4

CN1A
(WHT)

TBI.1

2WV2b

M

1

~

M

1

~

MP4

M

1

~

1

3

L
(1)N(3)

ORN

RED

BLU

BLU

RED

ORN

IHC

IHT

IH

642

531

A1

A2

A B

2

4

Immersion heater (1Ph3kW)(Option)

Power supply

to Immersion heater

~/N 230V 50Hz

1

2

CNIH

(ORN)

3

3WV

M

1

~

ECB2

1

2
4

6

CN01

(WHT)

Tool

Tool

Conductor

Conductor

Outline view Top view

<How to use TBO.1 to 4>

Connect them using either way as shown below.

X15

X12

TBO.3

X11

X10

1
2
3
4
5
6
7
8

Signal output

(Boiler)

Signal output

(Error)

Signal output

(Defrost)

Signal output

(Comp ON)

1
2
3
4
5
6

1
2
3
4
5
6

1
2
3
4
5
6
7
8

1
2
3
4
5
6

12 146 108

137 11945321

12 146 108

137 11945321

12 146 108

137 11945321

11

6-2. EHST20C-VM6C, EHST20C-VM6EC, EHPT20X-VM6C

Table 1 Signal Inputs

Name

Terminal block

Connector

Item OFF (Open) ON (Short)
IN1 TBI.1 13-14 — Room thermostat 1 input Refer to SW2-1 in <6-7. DIP switch setting>.
IN2 TBI.1 11-12 — Flow switch 1 input Refer to SW2-2 in <6-7. DIP switch setting>.
IN3 TBI.1 9-10 — Flow switch 2 input (Zone1) Refer to SW3-2 in <6-7. DIP switch setting>.
IN4 TBI.1 7-8 — Demand control input Normal

Heat source OFF/ Boiler operation *2

IN5 TBI.1 5-6 — Outdoor thermostat input *1

Standard operation

Heater operation/ Boiler operation *2
IN6 TBI.1 3-4 — Room thermostat 2 input Refer to SW3-1 in <6-7. DIP switch setting>.
IN7 TBI.1 1-2 — Flow switch 3 input (Zone2) Refer to SW3-3 in <6-7. DIP switch setting>.
IN8 TBI.3 1-2 — Electric energy meter 1

Refer to <6-7. DIP switch setting>.IN9 TBI.3 3-4 — Electric energy meter 2

IN10

TBI.3 5-6 — Heat meter

*1. If using outdoor thermostat for controlling operation of heaters, the lifetime of the heaters and related parts

may be reduced.

*2. To turn on the boiler operation, use the main controller to select “Boiler” in “External input setting“ screen in

the service menu.

Table 2 Outputs

Name

Terminal block

Connector

Item OFF ON

OUT1

TBO.1 1-2 CNP1 Water circulation pump 1 output (Space heating & DHW) OFF ON

OUT2

TBO.1 3-4 — Water circulation pump 2 output (Space heating for Zone1) OFF ON

OUT3

TBO.1 5-6 —

Water circulation pump 3 output (Space heating for Zone2) *1

OFF ON

2-way valve 2b output *2

OUT4

TBO.2 4-6 CNV1 3-way valve output Heating DHW

OUT5

TBO.2 1-2

— Mixing valve output *1 Stop

Close

TBO.2 2-3 Open

OUT6

—

CNBH 1-3

Booster heater 1 output OFF ON

OUT7

—

CNBH 5-7

Booster heater 2 output OFF ON

OUT9

TBO.4 3-4 CNIH Immersion heater output OFF ON

OUT10

TBO.3 1-2 — Boiler output OFF ON

OUT11

TBO.3 3-4 — Error output Normal Error

OUT12

TBO.3 5-6 — Defrost output Normal Defrost

OUT13

TBO.4 1-2 — 2-way valve 2a output *2 OFF ON

OUT14

— CNP4 Water circulation pump 4 output (DHW) OFF ON

OUT15

TBO.3 7-8 — Comp ON signal OFF ON

Do not connect to the terminals that are indicated as “—” in the “Terminal block” eld.
*1. For 2-zone temperature control.
*2. For 2-zone valve ON/OFF control.

1. Symbols used in wiring diagram are, : connector, : terminal

block.

2. Indoor unit and outdoor unit connecting wires have polarities, make sure
to match terminal numbers (S1, S2, S3) for correct wirings,

3. Since the outdoor unit side electric wiring may change, be sure to check
the outdoor unit electric wiring diagram for service.

Symbol Name
TB1 Terminal block <Power supply, Outdoor unit>
ECB1

Earth leakage circuit breaker for booster heater

ECB2

Earth leakage circuit breaker for immersion heater

MP1

Water circulation pump 1(Space heating & DHW)

MP2

Water circulation pump 2 (Space heating for Zone1)(Local supply)

MP3

Water circulation pump 3 (Space heating for Zone2)(Local supply)

MP4 Water circulation pump 4 (DHW)
3WV 3-way valve
2WV2a 2-way valve (For Zone 1)(Local supply)
2WV2b 2-way valve (For Zone 2)(Local supply)
MXV Mixing valve (Local supply)
BHT Thermostat for booster heater
BHF Thermal fuse for booster heater
BH1 Booster heater 1
BH2 Booster heater 2
BHC1 Contactor for booster heater 1
BHC2 Contactor for booster heater 2
BHCP Contactor for booster heater protection
IHT Thermostat (xed temp.) for immersion heater
IH Immersion heater
IHC Contactor for immersion heater

Symbol Name
TH1 Thermistor (Room temp.)(Option)
TH2 Thermistor (Ref. liquid temp.)
THW1 Thermistor (Flow water temp.)
THW2 Thermistor (Return water temp.)
THW5 Thermistor (DHW tank water temp.)
THW6 Thermistor (Zone1 ow temp.)(Option)
THW7 Thermistor (Zone1 return temp.)(Option)
THW8 Thermistor (Zone2 ow temp.)(Option)
THW9 Thermistor (Zone2 return temp.)(Option)
THWB1 Thermistor (Boiler ow temp.)(Option)
THWB2 Thermistor (Boiler return temp.)(Option)
IN1 Room thermostat 1 (Local supply)
IN2 Flow switch 1 (Local supply)
IN3 Flow switch 2 (Local supply)
IN4 Demand control (Local supply)
IN5 Outdoor thermostat (Local supply)
IN6 Room thermostat 2 (Local supply)
IN7 Flow switch 3 (Local supply)
IN8 Electric energy meter 1 (Local supply)
IN9 Electric energy meter 2 (Local supply)
IN10 Heat meter (Local supply)
FLOW TEMP. CONTROLLER (FTC5)

TBO.1-4

Terminal block <Outputs>
TBI.1-3 Terminal block <Signal Inputs, Thermistor>
F1 Fuse (T10AL250V)
F2 Fuse (T6.3AL250V)
SW1-5 DIP switch *See 6-7. DIP switch setting.
X1-15 Relay
LED1 Power supply (FTC5)
LED2 Power supply (Main controller)
LED3 Communication (FTC5-Outdoor unit)
LED4 Reading or writing data to SD card
CNPWM

Pump speed control signal for MP1

CN108 SD card connector

OCH570

NL

S3S2S1

NL

S3S2S1

To outdoor

unit

TB1

ORN

ORN

YLW

YLW

GRN/YLW

To outdoor

unit

Power supply
~/N 230V 50Hz

TB1

ORN

BLU

RED

BLU

RED

YLW

GRN/YLW

1

3

CN3C
(BLU)

BLK

BLK

BLK

BLK

1

3

ORN

BRN

CN3C
(BLU)

ORN

ORN

BRN

YLW

Indoor unit powered

by independent source

Indoor unit powered

via outdoor unit

CIRCUIT

BREAKER

1

3

CN3C
(BLU)

1

3

CNPWM

(WHT)

LED1

LED2

LED3

LED4

CN108

5

1

Wireless receiver

(Option)

WiFi adapter

(Option)

5

1

5

1

CNRF
(WHT)

CN105

(RED)

1
2
3
4
5
6

1

3

5

7

1

5

Close

Open

N

X6

X15

X12

X7

TBO.4

TBO.3

TBO.2

TBO.1

F1

F2

M

2WV2a

MXV

M

1

~

MP2

MP1

M

1

~

1

3

1

3

CNV1

(WHT)

1

3

CNBHT

(BLK)
CNBC
(GRY)

CNBH
(WHT)

X11

X9

X8

X13

X10

X4

X14

X3

X2

X1

X5B

X5A

1
2
3
4
5
6
7
8

1
2
3
4
5
6

1
2
3
4
5
6

1

1

3

3

3

CNP1
(WHT)

CNP4
(RED)

CNPWM

(WHT)

TBO.1

TBO.2

TBO.3

TBO.4

CNP1
(WHT)

CNP4
(RED)

CNV1
(WHT)

CN22
(BLU)

CNIT

(BLU)

CN01
(WHT)

F2 F1

6.3A 250V 10A 250V

SW1

SW2

SW3

SW4

SW5

1

8

1

8

1

1

5

1
3

1
3

8

1

1
2
3
4
5
6

1
2
3
4
5
6

1
2
3
4
5
6
7
8

1
2
3
4
5
6

8

1

6

CN01
(WHT)

CN01
(WHT)

2

1

4
6

2

1

1
2
4
6

4
6

CNBH
(WHT)

CNBC
(GRY)

1

1

3

1
2

1
2

1
2

CNBHT

(BLK)

1

3

7

1

3

CNIH

(ORN)

1

4

1

3

CNW5
(WHT)

CN21
(YLW)

CNW12

(RED)

CN20

(RED)

TBI.2

CNIH

(ORN)

MP3

M

1

~

2 2 2

L2
(3)L1(1)L3(5)

BHCP

BLK

BLK

WHT

WHTWHT

BLK

REDRED

BLU/No.4

WHT/No.2

WHT/No.3

WHT/No.1

BLU/No.5

BLU/No.6

RED

VLT

VLT

PNK

PNK

WHT

WHT

GRY

GRY

BHC2

BHC1

BHT

642

531

A1

A2

642

531

A1

A2

BH1

BHF

BH2

2

4 6

Power supply

to Booster heater

642

531

A1

A2

CNBH
(WHT)

CNBHT

(BLK)

2

2

2

2

2

CNBC
(GRY)

1

1

3

5

7

3

1

3

3~ 400V 50Hz

TBI.3

1

4

CN1A
(WHT)

TBI.1

2WV2b

M

1

~

M

1

~

MP4

M

1

~

1

3

L
(1)N(3)

ORN

RED

BLU

BLU

RED

ORN

IHC

IHT

IH

642

531

A1

A2

A B

2

4

Immersion heater (1Ph3kW)(Option)

Power supply

to Immersion heater

~/N 230V 50Hz

1

2

CNIH
(ORN)

3

Signal output

(Boiler)

Signal output

(Error)

Signal output

(Defrost)

Signal output

(Comp ON)

ECB1

ECB2

1

2
4

6

CN01

(WHT)

3WV

M

1

~

12 146 108

137 11945321

12 146 108

137 11945321

12 146 108

137 11945321

TBI.1

TBI.2

1310 12 141174 65 932 811310 12 141174 65 932 811310 12 141174 65 932 81

IN6

IN1

IN2

IN3

IN4

IN5

IN7

THW8

THW7

THW6

THW9

THWB1

THWB2

t°t°t°t°t°t

°

Main

controller

1

+

-+-+-

2

1

2

CN20

(RED)

TH1

t

°

1

3

CN21

(YLW)

TH2

t

°

1

4

THW1

THW2

CNW12

(RED)

t°t

°

1

2

THW5

CNW5

(WHT)

t

°

CN22
(BLU)

TAB1

IN8

IN9

IN10

TBI.3

Tool

Tool

Conductor

Conductor

Outline view Top view

<How to use TBO.1 to 4>

Connect them using either way as shown below.

12

6-3. EHST20C-YM9C, EHST20C-YM9EC, EHPT20X-YM9C

1. Symbols used in wiring diagram are, : connector, : terminal
block.

2. Indoor unit and outdoor unit connecting wires have polarities, make sure
to match terminal numbers (S1, S2, S3) for correct wirings,

3. Since the outdoor unit side electric wiring may change, be sure to check
the outdoor unit electric wiring diagram for service.

Table 1 Signal Inputs

Name

Terminal block

Connector

Item OFF (Open) ON (Short)
IN1 TBI.1 13-14 — Room thermostat 1 input Refer to SW2-1 in <6-7. DIP switch setting>.
IN2 TBI.1 11-12 — Flow switch 1 input Refer to SW2-2 in <6-7. DIP switch setting>.
IN3 TBI.1 9-10 — Flow switch 2 input (Zone1) Refer to SW3-2 in <6-7. DIP switch setting>.
IN4 TBI.1 7-8 — Demand control input Normal

Heat source OFF/ Boiler operation *2

IN5 TBI.1 5-6 — Outdoor thermostat input *1 Standard operation

Heater operation/ Boiler operation *2
IN6 TBI.1 3-4 — Room thermostat 2 input Refer to SW3-1 in <6-7. DIP switch setting>.
IN7 TBI.1 1-2 — Flow switch 3 input (Zone2) Refer to SW3-3 in <6-7. DIP switch setting>.
IN8 TBI.3 1-2 — Electric energy meter 1

Refer to <6-7. DIP switch setting>.IN9 TBI.3 3-4 — Electric energy meter 2

IN10

TBI.3 5-6 — Heat meter

*1. If using outdoor thermostat for controlling operation of heaters, the lifetime of the heaters and related parts

may be reduced.

*2. To turn on the boiler operation, use the main controller to select “Boiler” in “External input setting“ screen in

the service menu.

Table 2 Outputs

Name

Terminal block

Connector

Item OFF ON

OUT1

TBO.1 1-2 CNP1 Water circulation pump 1 output (Space heating & DHW) OFF ON

OUT2

TBO.1 3-4 — Water circulation pump 2 output (Space heating for Zone1) OFF ON

OUT3

TBO.1 5-6 —

Water circulation pump 3 output (Space heating for Zone2) *1

OFF ON

2-way valve 2b output *2

OUT4

TBO.2 4-6 CNV1 3-way valve output Heating DHW

OUT5

TBO.2 1-2

— Mixing valve output *1 Stop

Close

TBO.2 2-3 Open

OUT6

—

CNBH 1-3

Booster heater 1 output OFF ON

OUT7

—

CNBH 5-7

Booster heater 2 output OFF ON

OUT9

TBO.4 3-4 CNIH Immersion heater output OFF ON

OUT10

TBO.3 1-2 — Boiler output OFF ON

OUT11

TBO.3 3-4 — Error output Normal Error

OUT12

TBO.3 5-6 — Defrost output Normal Defrost

OUT13

TBO.4 1-2 — 2-way valve 2a output *2 OFF ON

OUT14

— CNP4 Water circulation pump 4 output (DHW) OFF ON

OUT15

TBO.3 7-8 — Comp ON signal OFF ON

Do not connect to the terminals that are indicated as “—” in the “Terminal block” eld.
*1. For 2-zone temperature control.
*2. For 2-zone valve ON/OFF control.

Symbol Name
TB1 Terminal block <Power supply, Outdoor unit>
ECB1

Earth leakage circuit breaker for booster heater

ECB2

Earth leakage circuit breaker for immersion heater

MP1

Water circulation pump 1(Space heating & DHW)

MP2

Water circulation pump 2 (Space heating for Zone1)(Local supply)

MP3

Water circulation pump 3 (Space heating for Zone2)(Local supply)

MP4 Water circulation pump 4 (DHW)
3WV 3-way valve
2WV2a 2-way valve (For Zone 1)(Local supply)
2WV2b 2-way valve (For Zone 2)(Local supply)
MXV Mixing valve (Local supply)
BHT Thermostat for booster heater
BHF Thermal fuse for booster heater
BH1 Booster heater 1
BH2 Booster heater 2
BHC1 Contactor for booster heater 1
BHC2 Contactor for booster heater 2
BHCP Contactor for booster heater protection
IHT Thermostat (xed temp.) for immersion heater
IH Immersion heater
IHC Contactor for immersion heater

Symbol Name
TH1 Thermistor (Room temp.)(Option)
TH2 Thermistor (Ref. liquid temp.)
THW1 Thermistor (Flow water temp.)
THW2 Thermistor (Return water temp.)
THW5 Thermistor (DHW tank water temp.)
THW6 Thermistor (Zone1 ow temp.)(Option)
THW7 Thermistor (Zone1 return temp.)(Option)
THW8 Thermistor (Zone2 ow temp.)(Option)
THW9 Thermistor (Zone2 return temp.)(Option)
THWB1 Thermistor (Boiler ow temp.)(Option)
THWB2 Thermistor (Boiler return temp.)(Option)
IN1 Room thermostat 1 (Local supply)
IN2 Flow switch 1 (Local supply)
IN3 Flow switch 2 (Local supply)
IN4 Demand control (Local supply)
IN5 Outdoor thermostat (Local supply)
IN6 Room thermostat 2 (Local supply)
IN7 Flow switch 3 (Local supply)
IN8 Electric energy meter 1 (Local supply)
IN9 Electric energy meter 2 (Local supply)
IN10 Heat meter (Local supply)
FLOW TEMP. CONTROLLER (FTC5)

TBO.1-4

Terminal block <Outputs>
TBI.1-3 Terminal block <Signal Inputs, Thermistor>
F1 Fuse (T10AL250V)
F2 Fuse (T6.3AL250V)
SW1-5 DIP switch *See 6-7. DIP switch setting.
X1-15 Relay
LED1 Power supply (FTC5)
LED2 Power supply (Main controller)
LED3 Communication (FTC5-Outdoor unit)
LED4 Reading or writing data to SD card
CNPWM

Pump speed control signal for MP1

CN108 SD card connector

OCH570

2 2 2

ECB1

L2
(3)L1(1)L3(5)

BHCP

BLK

BLK

WHT

WHTWHT

BLK

REDRED

BLU/No.4

WHT/No.2

WHT/No.3

WHT/No.1

BLU/No.5

BLU/No.6

RED

VLT

VLT

PNK

PNK

GRY

GRY

BHC2

BHC1

BHT

642

531

A1

A2

642

531

A1

A2

BH1

BHF

BH2

2

4

6

Power supply

to Booster heater

642

531

A1

A2

2

2

2

2

2

1

1

3

5

7

3

1

3

3~ 230V 50Hz

CNBHT
(BLK)

CNBC
(GRY)

CNBH
(WHT)

WHT

WHT

1

3

5

7

X6

X7

1

3

1

3

CNBHT

(BLK)
CNBC
(GRY)

CNBH
(WHT)

NL

S3S2S1

NL

S3S2S1

To outdoor

unit

TB1

ORN

ORN

YLW

YLW

GRN/YLW

To outdoor

unit

Power supply
~/N 230V 50Hz

TB1

ORN

BLU

RED

BLU

RED

YLW

GRN/YLW

1

3

CN3C
(BLU)

BLK

BLK

BLK

BLK

1

3

ORN

BRN

CN3C
(BLU)

ORN

ORN

BRN

YLW

Indoor unit powered

by independent source

Indoor unit powered

via outdoor unit

CIRCUIT

BREAKER

1

3

CN3C
(BLU)

1

3

CNPWM

(WHT)

LED1

LED2

LED3

LED4

TBI.1

TBI.2

1310 12 141174 65 932 811310 12 141174 65 932 811310 12 141174 65 932 81

IN6

IN1

IN2

IN3

IN4

IN5

IN7

THW8

THW7

THW6

THW9

THWB1

THWB2

t°t°t°t°t°t

°

Main

controller

1

+

-+-+-

2

1

2

CN20

(RED)

TH1

t

°

1

3

CN21

(YLW)

TH2

t

°

1

4

THW1

THW2

CNW12

(RED)

t°t

°

1

2

THW5

CNW5

(WHT)

t

°

CN108

5

1

Wireless receiver

(Option)

WiFi adapter

(Option)

5

1

5

1

CNRF
(WHT)

CN105
(RED)

CN22
(BLU)

1

5

Close

Open

N

TBO.2

TBO.1

F1

F2

MXV

M

1

~

MP2

MP1

M

1

~

CNV1
(WHT)

X4

X14

X3

X2

X1

X5B

X5A
1
2
3
4
5
6

1
2
3
4
5
6

1

1

3

3

3

CNP1
(WHT)

CNP4
(RED)

CNPWM
(WHT)

TBO.1

TBO.2

TBO.3

TBO.4

CNP1

(WHT)

CNP4
(RED)

CNV1

(WHT)

CN22
(BLU)

CNIT
(BLU)

TAB1

CN01

(WHT)

F2 F1

6.3A 250V 10A 250V

SW1

SW2

SW3

SW4

SW5

1

8

1

8

1

1

5

1
3

1
3

8

1

8

1

6

CN01
(WHT)

CN01

(WHT)

2

1

4
6

2

1

1
2
4
6

4
6

CNBH
(WHT)

CNBC
(GRY)

1

1

3

1
2

1
2

1
2

CNBHT

(BLK)

1

3

7

1

3

CNIH

(ORN)

1

4

1

3

CNW5
(WHT)

CN21
(YLW)

CNW12

(RED)

CN20
(RED)

TBI.2

MP3

M

1

~

IN8

IN9

IN10

TBI.3

TBI.3

1

4

CN1A

(WHT)

TBI.1

2WV2b

M

1

~

M

1

~

MP4

M

1

~

1

3

L

(1)N(3)

ORN

RED

BLU

BLU

RED

ORN

IHC

IHT

IH

642

531

A1

A2

A B

2

4

Immersion heater (1Ph3kW)(Option)

Power supply

to Immersion heater

~/N 230V 50Hz

1

2

CNIH
(ORN)

3

3WV

M

1

~

ECB2

1

2
4

6

CN01
(WHT)

Tool

Tool

Conductor

Conductor

Outline view Top view

<How to use TBO.1 to 4>

Connect them using either way as shown below.

X15

X12

TBO.3

X11

X10
1

2
3
4
5
6
7
8

Signal output

(Boiler)

Signal output

(Error)

Signal output

(Defrost)

Signal output

(Comp ON)

1
2
3
4
5
6

TBO.4

M

2WV2a

1

3

X9

X8

X13

CNIH

(ORN)

1
2
3
4
5
6

1
2
3
4
5
6

1
2
3
4
5
6
7
8

1
2
3
4
5
6

12 146 108

137 11945321

12 146 108

137 11945321

12 146 108

137 11945321

13

6-4. EHST20C-TM9C, EHPT20X-TM9C

Table 1 Signal Inputs

Name

Terminal block

Connector

Item OFF (Open) ON (Short)
IN1 TBI.1 13-14 — Room thermostat 1 input Refer to SW2-1 in <6-7. DIP switch setting>.
IN2 TBI.1 11-12 — Flow switch 1 input Refer to SW2-2 in <6-7. DIP switch setting>.
IN3 TBI.1 9-10 — Flow switch 2 input (Zone1) Refer to SW3-2 in <6-7. DIP switch setting>.
IN4 TBI.1 7-8 — Demand control input Normal Heat source OFF/ Boiler operation *2
IN5 TBI.1 5-6 — Outdoor thermostat input *1 Standard operation Heater operation/ Boiler operation *2
IN6 TBI.1 3-4 — Room thermostat 2 input Refer to SW3-1 in <6-7. DIP switch setting>.
IN7 TBI.1 1-2 — Flow switch 3 input (Zone2) Refer to SW3-3 in <6-7. DIP switch setting>.
IN8 TBI.3 1-2 — Electric energy meter 1

Refer to <6-7. DIP switch setting>.IN9 TBI.3 3-4 — Electric energy meter 2

IN10

TBI.3 5-6 — Heat meter

*1. If using outdoor thermostat for controlling operation of heaters, the lifetime of the heaters and related parts may

be reduced.

*2. To turn on the boiler operation, use the main controller to select “Boiler” in “External input setting“ screen in the

service menu.

Table 2 Outputs

Name

Terminal block

Connector

Item OFF ON

OUT1

TBO.1 1-2 CNP1 Water circulation pump 1 output (Space heating & DHW) OFF ON

OUT2

TBO.1 3-4 — Water circulation pump 2 output (Space heating for Zone1) OFF ON

OUT3

TBO.1 5-6 —

Water circulation pump 3 output (Space heating for Zone2) *1

OFF ON

2-way valve 2b output *2

OUT4

TBO.2 4-6 CNV1 3-way valve output Heating DHW

OUT5

TBO.2 1-2

— Mixing valve output *1 Stop

Close

TBO.2 2-3 Open

OUT6

—

CNBH 1-3

Booster heater 1 output OFF ON

OUT7

—

CNBH 5-7

Booster heater 2 output OFF ON

OUT9

TBO.4 3-4 CNIH Immersion heater output OFF ON

OUT10

TBO.3 1-2 — Boiler output OFF ON

OUT11

TBO.3 3-4 — Error output Normal Error

OUT12

TBO.3 5-6 — Defrost output Normal Defrost

OUT13

TBO.4 1-2 — 2-way valve 2a output *2 OFF ON

OUT14

— CNP4 Water circulation pump 4 output (DHW) OFF ON

OUT15

TBO.3 7-8 — Comp ON signal OFF ON

Do not connect to the terminals that are indicated as “—” in the “Terminal block” eld.
*1. For 2-zone temperature control.
*2. For 2-zone valve ON/OFF control.

Symbol Name
TB1 Terminal block <Power supply, Outdoor unit>
ECB1

Earth leakage circuit breaker for booster heater

ECB2

Earth leakage circuit breaker for immersion heater

MP1

Water circulation pump 1(Space heating & DHW)

MP2

Water circulation pump 2 (Space heating for Zone1)(Local supply)

MP3

Water circulation pump 3 (Space heating for Zone2)(Local supply)

MP4 Water circulation pump 4 (DHW)
3WV 3-way valve
2WV2a 2-way valve (For Zone 1)(Local supply)
2WV2b 2-way valve (For Zone 2)(Local supply)
MXV Mixing valve (Local supply)
BHT Thermostat for booster heater
BHF Thermal fuse for booster heater
BH1 Booster heater 1
BH2 Booster heater 2
BHC1 Contactor for booster heater 1
BHC2 Contactor for booster heater 2
BHCP Contactor for booster heater protection
IHT Thermostat (xed temp.) for immersion heater
IH Immersion heater
IHC Contactor for immersion heater

Symbol Name
TH1 Thermistor (Room temp.)(Option)
TH2 Thermistor (Ref. liquid temp.)
THW1 Thermistor (Flow water temp.)
THW2 Thermistor (Return water temp.)
THW5 Thermistor (DHW tank water temp.)
THW6 Thermistor (Zone1 ow temp.)(Option)
THW7 Thermistor (Zone1 return temp.)(Option)
THW8 Thermistor (Zone2 ow temp.)(Option)
THW9 Thermistor (Zone2 return temp.)(Option)
THWB1 Thermistor (Boiler ow temp.)(Option)
THWB2 Thermistor (Boiler return temp.)(Option)
IN1 Room thermostat 1 (Local supply)
IN2 Flow switch 1 (Local supply)
IN3 Flow switch 2 (Local supply)
IN4 Demand control (Local supply)
IN5 Outdoor thermostat (Local supply)
IN6 Room thermostat 2 (Local supply)
IN7 Flow switch 3 (Local supply)
IN8 Electric energy meter 1 (Local supply)
IN9 Electric energy meter 2 (Local supply)
IN10 Heat meter (Local supply)
FLOW TEMP. CONTROLLER (FTC5)

TBO.1-4

Terminal block <Outputs>
TBI.1-3 Terminal block <Signal Inputs, Thermistor>
F1 Fuse (T10AL250V)
F2 Fuse (T6.3AL250V)
SW1-5 DIP switch *See 6-7. DIP switch setting.
X1-15 Relay
LED1 Power supply (FTC5)
LED2 Power supply (Main controller)
LED3 Communication (FTC5-Outdoor unit)
LED4 Reading or writing data to SD card
CNPWM

Pump speed control signal for MP1

CN108 SD card connector

1. Symbols used in wiring diagram are, : connector, : terminal
block.

2. Indoor unit and outdoor unit connecting wires have polarities, make
sure to match terminal numbers (S1, S2, S3) for correct wirings,

3. Since the outdoor unit side electric wiring may change, be sure to
check the outdoor unit electric wiring diagram for service.

OCH570

1

3

5

7

X6

X7

1

3

1

3

CNBHT

(BLK)
CNBC
(GRY)

CNBH
(WHT)

NL

S3S2S1

NL

S3S2S1

To outdoor

unit

TB1

ORN

ORN

YLW

YLW

GRN/YLW

To outdoor

unit

Power supply

~/N 230V 50Hz

TB1

ORN

BLU

RED

BLU

RED

YLW

GRN/YLW

1

3

CN3C
(BLU)

BLK

BLK

BLK

BLK

1

3

ORN

BRN

CN3C
(BLU)

ORN

ORN

BRN

YLW

Indoor unit powered

by independent source

Indoor unit powered

via outdoor unit

CIRCUIT

BREAKER

1

3

CN3C
(BLU)

1

3

CNPWM

(WHT)

LED1

LED2

LED3

LED4

TBI.1

TBI.2

1310 12 141174 65 932 811310 12 141174 65 932 811310 12 141174 65 932 81

IN6

IN1

IN2

IN3

IN4

IN5

IN7

THW8

THW7

THW6

THW9

THWB1

THWB2

t°t°t°t°t°t

°

Main

controller

1

+

-+-+-

2

1

2

CN20

(RED)

TH1

t

°

1

3

CN21

(YLW)

TH2

t

°

1

4

THW1

THW2

CNW12

(RED)

t°t

°

1

2

THW5

CNW5

(WHT)

t

°

CN108

5

1

Wireless receiver

(Option)

WiFi adapter

(Option)

5

1

5

1

CNRF
(WHT)

CN105
(RED)

CN22
(BLU)

1

5

Close

Open

N

TBO.2

TBO.1

F1

F2

MXV

M

1

~

MP2

MP1

M

1

~

CNV1

(WHT)

X4

X14

X3

X2

X1

X5B

X5A
1
2
3
4
5
6

1
2
3
4
5
6

1

1

3

3

3

CNP1
(WHT)

CNP4
(RED)

CNPWM

(WHT)

TBO.1

TBO.2

TBO.3

TBO.4

CNP1
(WHT)

CNP4
(RED)

CNV1
(WHT)

CN22
(BLU)

CNIT
(BLU)

TAB1

CN01
(WHT)

F2 F1

6.3A 250V 10A 250V

SW1

SW2

SW3

SW4

SW5

1

8

1

8

1

1

5

1
3

1
3

8

1

1
2
3
4
5
6

1
2
3
4
5
6

1
2
3
4
5
6
7
8

1
2
3
4
5
6

8

1

6

CN01
(WHT)

CN01

(WHT)

2

1

4
6

2

1

1
2
4
6

4
6

CNBH

(WHT)

CNBC
(GRY)

1

1

3

1
2

1
2

1
2

CNBHT

(BLK)

1

3

7

1

3

CNIH

(ORN)

1

4

1

3

CNW5
(WHT)

CN21

(YLW)

CNW12

(RED)

CN20
(RED)

TBI.2

12 146 108

137 11945321

12 146 108

137 11945321

12 146 108

137 11945321

MP3

M

1

~

IN8

IN9

IN10

TBI.3

TBI.3

1

4

CN1A
(WHT)

TBI.1

2WV2b

M

1

~

M

1

~

MP4

M

1

~

1

3

L

(1)N(3)

ORN

RED

BLU

BLU

RED

ORN

IHC

IHT

IH

642

531

A1

A2

A B

2

4

Immersion heater (1Ph3kW)(Option)

Power supply

to Immersion heater

~/N 230V 50Hz

1

2

CNIH
(ORN)

3

3WV

M

1

~

ECB2

1

2
4

6

CN01

(WHT)

X15

X12

TBO.3

X11

X10
1

2
3
4
5
6
7
8

Signal output

(Boiler)

Signal output

(Error)

Signal output

(Defrost)

Signal output

(Comp ON)

1
2
3
4
5
6

TBO.4

M

2WV2a

1

3

X9

X8

X13

CNIH

(ORN)

Tool

Tool

Conductor

Conductor

Outline view Top view

<How to use TBO.1 to 4>

Connect them using either way as shown below.

14

6-5. EHST20C-MEC, EHST20D-MEC, EHST20D-MHC

Table 1 Signal Inputs

Name

Terminal block

Connector

Item OFF (Open) ON (Short)
IN1 TBI.1 13-14 — Room thermostat 1 input Refer to SW2-1 in <6-7. DIP switch setting>.
IN2 TBI.1 11-12 — Flow switch 1 input Refer to SW2-2 in <6-7. DIP switch setting>.
IN3 TBI.1 9-10 — Flow switch 2 input (Zone1) Refer to SW3-2 in <6-7. DIP switch setting>.
IN4 TBI.1 7-8 — Demand control input Normal Heat source OFF/ Boiler operation *2
IN5 TBI.1 5-6 — Outdoor thermostat input *1 Standard operation Heater operation/ Boiler operation *2
IN6 TBI.1 3-4 — Room thermostat 2 input Refer to SW3-1 in <6-7. DIP switch setting>.
IN7 TBI.1 1-2 — Flow switch 3 input (Zone2) Refer to SW3-3 in <6-7. DIP switch setting>.
IN8 TBI.3 1-2 — Electric energy meter 1

Refer to <6-7. DIP switch setting>.IN9 TBI.3 3-4 — Electric energy meter 2

IN10

TBI.3 5-6 — Heat meter

*1. If using outdoor thermostat for controlling operation of heaters, the lifetime of the heaters and related parts may

be reduced.

*2. To turn on the boiler operation, use the main controller to select “Boiler” in “External input setting“ screen in the

service menu.

Table 2 Outputs

Name

Terminal block

Connector

Item OFF ON

OUT1

TBO.1 1-2 CNP1 Water circulation pump 1 output (Space heating & DHW) OFF ON

OUT2

TBO.1 3-4 — Water circulation pump 2 output (Space heating for Zone1) OFF ON

OUT3

TBO.1 5-6 —

Water circulation pump 3 output (Space heating for Zone2) *1

OFF ON

2-way valve 2b output *2

OUT4

TBO.2 4-6 CNV1 3-way valve output Heating DHW

OUT5

TBO.2 1-2

— Mixing valve output *1 Stop

Close

TBO.2 2-3 Open

OUT6

—

CNBH 1-3

Booster heater 1 output OFF ON

OUT7

—

CNBH 5-7

Booster heater 2 output OFF ON

OUT9

TBO.4 3-4 CNIH Immersion heater output OFF ON

OUT10

TBO.3 1-2 — Boiler output OFF ON

OUT11

TBO.3 3-4 — Error output Normal Error

OUT12

TBO.3 5-6 — Defrost output Normal Defrost

OUT13

TBO.4 1-2 — 2-way valve 2a output *2 OFF ON

OUT14

— CNP4 Water circulation pump 4 output (DHW) OFF ON

OUT15

TBO.3 7-8 — Comp ON signal OFF ON

Do not connect to the terminals that are indicated as “—” in the “Terminal block” eld.
*1. For 2-zone temperature control.
*2. For 2-zone valve ON/OFF control.

1. Symbols used in wiring diagram are, : connector,

: terminal block.

2. Indoor unit and outdoor unit connecting wires have polarities,

make sure to match terminal numbers (S1, S2, S3) for

correct wirings,

3. Since the outdoor unit side electric wiring may change, be
sure to check the outdoor unit electric wiring diagram for

service.

Symbol Name
TB1 Terminal block <Power supply, Outdoor unit>
ECB2

Earth leakage circuit breaker for immersion heater

MP1

Water circulation pump 1(Space heating & DHW)

MP2

Water circulation pump 2 (Space heating for Zone1)(Local supply)

MP3

Water circulation pump 3 (Space heating for Zone2)(Local supply)

MP4 Water circulation pump 4 (DHW)
3WV 3-way valve
2WV2a 2-way valve (For Zone 1)(Local supply)
2WV2b 2-way valve (For Zone 2)(Local supply)
MXV Mixing valve (Local supply)
IHT Thermostat (xed temp.) for immersion heater
IH Immersion heater
IHC Contactor for immersion heater

Symbol Name
TH1 Thermistor (Room temp.)(Option)
TH2 Thermistor (Ref. liquid temp.)
THW1 Thermistor (Flow water temp.)
THW2 Thermistor (Return water temp.)
THW5 Thermistor (DHW tank water temp.)
THW6 Thermistor (Zone1 ow temp.)(Option)
THW7 Thermistor (Zone1 return temp.)(Option)
THW8 Thermistor (Zone2 ow temp.)(Option)
THW9 Thermistor (Zone2 return temp.)(Option)
THWB1 Thermistor (Boiler ow temp.)(Option)
THWB2 Thermistor (Boiler return temp.)(Option)
IN1 Room thermostat 1 (Local supply)
IN2 Flow switch 1 (Local supply)
IN3 Flow switch 2 (Local supply)
IN4 Demand control (Local supply)
IN5 Outdoor thermostat (Local supply)
IN6 Room thermostat 2 (Local supply)
IN7 Flow switch 3 (Local supply)
IN8 Electric energy meter 1 (Local supply)
IN9 Electric energy meter 2 (Local supply)
IN10 Heat meter (Local supply)
FLOW TEMP. CONTROLLER (FTC5)

TBO.1-4

Terminal block <Outputs>
TBI.1-3 Terminal block <Signal Inputs, Thermistor>
F1 Fuse (T10AL250V)
F2 Fuse (T6.3AL250V)
SW1-5 DIP switch *See 6-7. DIP switch setting.
X1-15 Relay
LED1 Power supply (FTC5)
LED2 Power supply (Main controller)
LED3 Communication (FTC5-Outdoor unit)
LED4 Reading or writing data to SD card
CNPWM

Pump speed control signal for MP1

CN108 SD card connector

OCH570

Tool

Tool

Conductor

Conductor

Outline view Top view

<How to use TBO.1 to 4>

Connect them using either way as shown below.

NL

S3S2S1

NL

S3S2S1

To outdoor

unit

TB1

ORN

ORN

YLW

YLW

GRN/YLW

To outdoor

unit

Power supply
~/N 230V 50Hz

TB1

ORN

BLU

RED

BLU

RED

YLW

GRN/YLW

1

3

CN3C
(BLU)

BLK

BLK

BLK

BLK

1

3

ORN

BRN

CN3C
(BLU)

ORN

ORN

BRN

YLW

Indoor unit powered

by independent source

Indoor unit powered

via outdoor unit

CIRCUIT

BREAKER

1

3

CN3C
(BLU)

1

3

CNPWM

(WHT)

LED1

LED2

LED3

LED4

TBI.1

TBI.2

1310 12 141174 65 932 811310 12 141174 65 932 811310 12 141174 65 932 81

IN6

IN1

IN2

IN3

IN4

IN5

IN7

THW8

THW7

THW6

THW9

THWB1

THWB2

t°t°t°t°t°t

°

Main

controller

1

+

-+-+-

2

1

2

CN20

(RED)

TH1

t

°

1

3

CN21

(YLW)

TH2

t

°

1

4

THW1

THW2

CNW12

(RED)

t°t

°

1

2

THW5

CNW5

(WHT)

t

°

CN108

5

1

Wireless receiver

(Option)

WiFi adapter

(Option)

5

1

5

1

CNRF
(WHT)

CN105

(RED)

CN22
(BLU)

1

3

5

7

1

5

Close

Open

N

X6

X7

TBO.2

TBO.1

F1

F2

MXV

M

1

~

MP2

MP1

M

1

~

1

3

CNV1

(WHT)

1

3

CNBHT

(BLK)
CNBC
(GRY)

CNBH
(WHT)

X4

X14

X3

X2

X1

X5B

X5A
1
2
3
4
5
6

1
2
3
4
5
6

1

1

3

3

3

CNP1
(WHT)

CNP4
(RED)

CNPWM

(WHT)

TBO.1

TBO.2

TBO.3

TBO.4

CNP1
(WHT)

CNP4
(RED)

CNV1
(WHT)

CN22
(BLU)

CNIT
(BLU)

TAB1

CN01
(WHT)

F2 F1

6.3A 250V 10A 250V

SW1

SW2

SW3

SW4

SW5

1

8

1

8

1

1

5

1
3

1
3

8

1

8

1

6

CN01
(WHT)

CN01
(WHT)

2

1

4
6

2

1

1
2
4
6

4
6

CNBH

(WHT)

CNBC

(GRY)

1

1

3

1
2

1
2

1
2

CNBHT

(BLK)

1

3

7

1

3

CNIH
(ORN)

1

4

1

3

CNW5
(WHT)

CN21

(YLW)

CNW12

(RED)

CN20
(RED)

TBI.2

MP3

M

1

~

IN8

IN9

IN10

TBI.3

TBI.3

1

4

CN1A

(WHT)

TBI.1

2WV2b

M

1

~

M

1

~

MP4

M

1

~

1

3

L

(1)N(3)

ORN

RED

BLU

BLU

RED

ORN

IHC

IHT

IH

642

531

A1

A2

A B

2

4

Immersion heater (1Ph3kW)

Power supply

to Immersion heater

~/N 230V 50Hz

1

2

CNIH
(ORN)

3

3WV

M

1

~

ECB2

1

2
4

6

CN01

(WHT)

X15

X12

TBO.3

X11

X10
1

2
3
4
5
6
7
8

Signal output

(Boiler)

Signal output

(Error)

Signal output

(Defrost)

Signal output

(Comp ON)

1
2
3
4
5
6

TBO.4

M

2WV2a

1

3

X9

X8

X13

CNIH
(ORN)

1
2
3
4
5
6

1
2
3
4
5
6

1
2
3
4
5
6
7
8

1
2
3
4
5
6

12 146 108

137 11945321

12 146 108

137 11945321

12 146 108

137 11945321

15

6-6.

EHPT20X-MHCW, EHST20C-MHCW, EHST20D-MHCW

1. Symbols used in wiring diagram are, : connector, :
terminal block.

2. Indoor unit and outdoor unit connecting wires have polarities, make
sure to match terminal numbers (S1, S2, S3) for correct wirings,

3. Since the outdoor unit side electric wiring may change, be sure to
check the outdoor unit electric wiring diagram for service.

Table 1 Signal Inputs

Name

Terminal block

Connector

Item OFF (Open) ON (Short)
IN1 TBI.1 13-14 — Room thermostat 1 input Refer to SW2-1 in <6-7. DIP switch setting>.
IN2 TBI.1 11-12 — Flow switch 1 input Refer to SW2-2 in <6-7. DIP switch setting>.
IN3 TBI.1 9-10 — Flow switch 2 input (Zone1) Refer to SW3-2 in <6-7. DIP switch setting>.
IN4 TBI.1 7-8 — Demand control input Normal Heat source OFF/ Boiler operation *2
IN5 TBI.1 5-6 — Outdoor thermostat input *1 Standard operation Heater operation/ Boiler operation *2
IN6 TBI.1 3-4 — Room thermostat 2 input Refer to SW3-1 in <6-7. DIP switch setting>.
IN7 TBI.1 1-2 — Flow switch 3 input (Zone2) Refer to SW3-3 in <6-7. DIP switch setting>.
IN8 TBI.3 1-2 — Electric energy meter 1

Refer to <6-7. DIP switch setting>.IN9 TBI.3 3-4 — Electric energy meter 2

IN10

TBI.3 5-6 — Heat meter

*1. If using outdoor thermostat for controlling operation of heaters, the lifetime of the heaters and related parts may

be reduced.

*2. To turn on the boiler operation, use the main controller to select “Boiler” in “External input setting“ screen in the

service menu.

Table 2 Outputs

Name

Terminal block

Connector

Item OFF ON

OUT1

TBO.1 1-2 CNP1 Water circulation pump 1 output (Space heating & DHW) OFF ON

OUT2

TBO.1 3-4 — Water circulation pump 2 output (Space heating for Zone1) OFF ON

OUT3

TBO.1 5-6 —

Water circulation pump 3 output (Space heating for Zone2) *1

OFF ON

2-way valve 2b output *2

OUT4

TBO.2 4-6 CNV1 3-way valve output Heating DHW

OUT5

TBO.2 1-2

— Mixing valve output *1 Stop

Close

TBO.2 2-3 Open

OUT6

—

CNBH 1-3

Booster heater 1 output OFF ON

OUT7

—

CNBH 5-7

Booster heater 2 output OFF ON

OUT9

TBO.4 3-4 CNIH Immersion heater output OFF ON

OUT10

TBO.3 1-2 — Boiler output OFF ON

OUT11

TBO.3 3-4 — Error output Normal Error

OUT12

TBO.3 5-6 — Defrost output Normal Defrost

OUT13

TBO.4 1-2 — 2-way valve 2a output *2 OFF ON

OUT14

— CNP4 Water circulation pump 4 output (DHW) OFF ON

OUT15

TBO.3 7-8 — Comp ON signal OFF ON

Do not connect to the terminals that are indicated as “—” in the “Terminal block” eld.
*1. For 2-zone temperature control.
*2. For 2-zone valve ON/OFF control.

Symbol Name
TB1 Terminal block <Power supply, Outdoor unit>
ECB2

Earth leakage circuit breaker for immersion heater

MP1

Water circulation pump 1(Space heating & DHW)

MP2

Water circulation pump 2 (Space heating for Zone1)(Local supply)

MP3

Water circulation pump 3 (Space heating for Zone2)(Local supply)

MP4 Water circulation pump 4 (DHW)
3WV 3-way valve
2WV2a 2-way valve (For Zone 1)(Local supply)
2WV2b 2-way valve (For Zone 2)(Local supply)
MXV Mixing valve (Local supply)
IHT Thermostat (xed temp.) for immersion heater
IH Immersion heater
IHC Contactor for immersion heater

Symbol Name
TH1 Thermistor (Room temp.)(Option)
TH2 Thermistor (Ref. liquid temp.)
THW1 Thermistor (Flow water temp.)
THW2 Thermistor (Return water temp.)
THW5 Thermistor (DHW tank water temp.)
THW6 Thermistor (Zone1 ow temp.)(Option)
THW7 Thermistor (Zone1 return temp.)(Option)
THW8 Thermistor (Zone2 ow temp.)(Option)
THW9 Thermistor (Zone2 return temp.)(Option)
THWB1 Thermistor (Boiler ow temp.)(Option)
THWB2 Thermistor (Boiler return temp.)(Option)
IN1 Room thermostat 1 (Local supply)
IN2 Flow switch 1 (Local supply)
IN3 Flow switch 2 (Local supply)
IN4 Demand control (Local supply)
IN5 Outdoor thermostat (Local supply)
IN6 Room thermostat 2 (Local supply)
IN7 Flow switch 3 (Local supply)
IN8 Electric energy meter 1 (Local supply)
IN9 Electric energy meter 2 (Local supply)
IN10 Heat meter (Local supply)
FLOW TEMP. CONTROLLER (FTC5)

TBO.1-4

Terminal block <Outputs>
TBI.1-3 Terminal block <Signal Inputs, Thermistor>
F1 Fuse (T10AL250V)
F2 Fuse (T6.3AL250V)
SW1-5 DIP switch *See 6-7. DIP switch setting.
X1-15 Relay
LED1 Power supply (FTC5)
LED2 Power supply (Main controller)
LED3 Communication (FTC5-Outdoor unit)
LED4 Reading or writing data to SD card
CNPWM

Pump speed control signal for MP1

CN108 SD card connector

OCH570

16

Automatic switch to backup heat source operation

Back-up heat source operation (*1) will automatically run when the outdoor unit stops abnormally. To enable the function, switch DIP SW 2-5 to ON. During the back­up operation, an error code(s) and the contact number will be displayed alternately. External output (OUT11) will be available.
To clear the fault(s), reset the power breakers on the indoor and outdoor units.

<Applicable error codes (*2)>
E6 to E9, ED, P6, P8, U1 to U8, UD, UE, UF, UL, UP

(*1) Prolonged running of the back-up operation may affect the life of the heat source.
(*2) For safety reasons, this function is not available for certain faults. (System operation must be stopped and only pump keeps running.)

6-7. DIP switch setting

Located on the FTC printed circuit board are 4 sets of small white switches
known as DIP switches. The DIP switch number is printed on the circuit board
next to the relevant switches. The word ON is printed on the circuit board and on
the DIP switch block itself. To move the switch you will need to use a pin or the

corner of a thin metal ruler or similar.

DIP switch settings are listed below in the table below.
Before changing any switch settings, ensure power supplies to indoor and out­door units are isolated/powered off.

DIP switch Function OFF ON

Default settings:

Indoor unit model

SW1

SW1-1 Boiler WITHOUT Boiler WITH Boiler OFF

SW1-2 Heat pump maximum outlet water temperature 55ºC 60ºC ON *1

SW1-3 DHW tank WITHOUT DHW tank WITH DHW tank ON

SW1-4 Immersion heater WITHOUT Immersion heater WITH Immersion heater

OFF:

EH*T20*-*C

ON : EH*T20*-*HC*

SW1-5 Booster heater WITHOUT Booster heater WITH Booster heater

OFF:

EH*T20*-M*C*

ON :

EH*T20*-*M 2/6/9*C

SW1-6 Booster heater function For heating only For heating and DHW

OFF:

EH*T20*-M*C*

ON :

EH*T20*-*M 2/6/9*C

SW1-7 Outdoor unit type Split type Packaged type

OFF: EHST20*-*M**C*
ON :

EHPT20X-*M**C*

SW1-8 Wireless remote controller

WITHOUT Wireless remote controller

WITH Wireless remote controller OFF

SW2

SW2-1 Room thermostat1 input (IN1) logic change

Zone1 operation stop at thermostat short

Zone1 operation stop at thermostat open

OFF

SW2-2 Flow switch1 input (IN2) logic change Failure detection at short Failure detection at open OFF

SW2-3 Booster heater capacity restriction Inactive Active

OFF: Except

EH*T20*-VM2*C

ON : EH*T20*-VM2*C

SW2-4 — — — OFF

SW2-5

Automatic switch to backup heat source operation

(When outdoor unit stops by error)

Inactive Active *2 OFF

SW2-6 Mixing tank WITHOUT Mixing tank WITH Mixing tank OFF

SW2-7 2-zone temperature control Inactive Active *6 OFF

SW2-8 Flow sensor WITHOUT Flow sensor WITH Flow sensor ON

SW3

SW3-1 Room thermostat 2 input (IN6) logic change

Zone2 operation stop at thermostat short

Zone2 operation stop at thermostat open

OFF

SW3-2 Flow switch 2 input (IN3) logic change Failure detection at short Failure detection at open OFF

SW3-3 Flow switch 3 input (IN7) logic change Failure detection at short Failure detection at open OFF

SW3-4 Electric energy meter WITHOUT Electric energy meter WITH Electric energy meter OFF

SW3-5 Heating mode function *3 Inactive Active ON

SW3-6 2-zone valve ON/OFF control Inactive Active OFF

SW3-7 Heat exchanger for DHW Coil in tank External plate HEX ON

SW3-8 Heat meter WITHOUT Heat meter WITH Heat meter OFF

SW4

SW4-1 — — — OFF

SW4-2 — — — OFF

SW4-3 — — — OFF

SW4-4

Indoor unit only operation (during installation work) *4

Inactive Active OFF

SW4-5 Emergency mode (Heater only operation) Normal

Emergency mode (Heater only operation)

OFF *5

SW4-6 Emergency mode (Boiler operation) Normal Emergency mode (Boiler operation) OFF *5

SW5

SW5-1 — — — OFF

SW5-2 — — — OFF

SW5-3

SW5-4

SW5-5

SW5-6

SW5-7

SW5-8 — — — OFF

Note: *1. When the cylinder unit is connected with a PUHZ-RP/SUHZ-SW outdoor unit of which maximum outlet water temperature is 55ºC, DIP SW1-2

must be changed to OFF.

*2. External output (OUT11) will be available. For safety reasons, this function is not available for certain errors. (In that case, system operation

must be stopped and only the water circulation pump keeps running.)

*3. This switch functions only when the cylinder unit is connected with a PUHZ-FRP outdoor unit. When another type of outdoor unit is con-

nected, the heating mode function is active regardless of the fact that this switch is ON or OFF.
*4. Space heating and DHW can be operated only in indoor unit, like an electric boiler. (Refer to "Indoor unit only operation" in page 44. )
*5. If emergency mode is no longer required, return the switch to OFF position.
*6. Active only when DIP SW3-6 is set to OFF.

SW1

SW3

SW4

SW2

SW5

SW5-3 SW5-4 SW5-5 SW5-6 SW5-7
EHST20C-*M*C* ON ON ON ON OFF
EHST20D-*M*C* ON OFF OFF ON OFF
EHPT20X-*M*C* OFF OFF OFF OFF OFF

Capacity code

OCH570

L

N

S1

S2

S3

S1

S2

S3

TB1

L

N

ECB1

L

N

ECB2

L

N

17

FIELD WIRING

7

Breaker abbreviation Meaning

ECB1 Earth leakage circuit breaker for booster heater
ECB2 Earth leakage circuit breaker for immersion heater
TB1 Terminal block 1

Earth

leakage

circuit

breaker

*1

Wiring

circuit

breaker

or

Isolating

switch

Outdoor unit

Power

supply
~/N
230 V

50 Hz

Power

supply

~/N

230 V

50 Hz

Power

supply

~/N

230 V

50 Hz

Wiring

circuit

breaker or

Isolating

switch

Wiring

circuit

breaker or

Isolating

switch

To control
board

For
booster
heater
(Primary circuit)

For
Immersion
heater
(DHW tank)

Cylinder unit

Option 1: Cylinder unit powered via outdoor unit

<1 phase>

<Figure 7-1>

Electrical connections 1 phase

Description Power supply Capacity Breaker Wiring

Booster heater (Primary circuit) ~/N 230 V 50 Hz 2 kW 16 A *1 2.5 mm²

6 kW 32 A *1 6.0 mm²

Immersion heater (DHW tank) ~/N 230 V 50 Hz 3 kW 16 A *1 2.5 mm²

Wiring

Wiring No.

× size (mm²)

Cylinder unit - Outdoor unit *2 3 × 1.5 (polar)

Cylinder unit - Outdoor unit earth *2 1 × Min. 1.5

Circuit

rating

Cylinder unit - Outdoor unit S1 - S2 *3 230 V AC

Cylinder unit - Outdoor unit S2 - S3 *3 24 V DC

*1. A breaker with at least 3.0 mm contact separation in each pole shall be provided. Use earth leakage breaker (NV).

The breaker shall be provided to ensure disconnection of all active phase conductors of the supply.

*2. Max. 45 m

If 2.5 mm² used, Max. 50 m
If 2.5 mm² used and S3 separated, Max. 80 m

*3. The values given in the table above are not always measured against the ground value.

Note: 1. Wiring size must comply with the applicable local and national codes.

2.Indoorunit/outdoorunitconnectingcordsshallnotbelighterthanpolychloroprenesheathedexiblecord.(Design60245IEC57)
Indoorunitpowersupplycordsshallnotbelighterthanpolychloroprenesheathedexiblecord.(Design60227IEC53)

3. Install an earth longer than other cables.

4.Pleasekeepenoughoutputcapacityofpowersupplyforeachheater.Insufcientpowersupplycapacitymightcausechattering.

*1 If the installed earth leakage circuit

breaker does not have an over-current

protection function, install a breaker with
that function along the same power line.

Affix label A that is included with the manuals near each
wiring diagram for cylinder unit and outdoor units.

OCH570

L1

L2

S1

S2

S3

TB1

L2

L3

ECB1

L

N

ECB2

N

L3

L1

S1

S2

S3

L

N

18

Power

supply
3N~
400 V

50 Hz

Earth

leakage

circuit

breaker

*1

Wiring

circuit

breaker

or

Isolating

switch

Power supply

3~ 400 V 50 Hz (EH*T20*-YM*C)
3~ 230 V 50 Hz (EH*T20*-TM*C)

Power

supply
~/N
230 V

50 Hz

Wiring

circuit

breaker

or

Isolating

switch

Wiring

circuit

breaker

or

Isolating

switch

For
booster
heater
(Primary circuit)

For
Immersion
heater
(DHW tank)

To control
board

Outdoor unit

Cylinder unit

<3 phase>

<Figure 7-2>

Electrical connections 3 phase

Description Power supply Capacity (Indoor unit Ref.) Breaker Wiring

Booster heater (Primary circuit)

3~ 400 V 50 Hz 9 kW 16 A *1 2.5 mm²
3~ 230 V 50 Hz 9 kW 32 A *1 6.0 mm²

Immersion heater (DHW tank) ~/N 230 V 50 Hz 3 kW 16 A *1 2.5 mm²

Wiring

Wiring No.

× size (mm²)

Cylinder unit - Outdoor unit *2 3 × 1.5 (polar)

Cylinder unit - Outdoor unit earth *2 1 × Min. 1.5

Circuit

rating

Cylinder unit - Outdoor unit S1 - S2 *3 230 V AC

Cylinder unit - Outdoor unit S2 - S3 *3 24 V DC

*1. A breaker with at least 3.0 mm contact separation in each pole shall be provided. Use earth leakage breaker (NV).

The breaker shall be provided to ensure disconnection of all active phase conductors of the supply.

*2. Max. 45 m

If 2.5 mm² used, Max. 50 m
If 2.5 mm² used and S3 separated, Max. 80 m

*3. The values given in the table above are not always measured against the ground value.

Note: 1. Wiring size must comply with the applicable local and national codes.

2.Indoorunit/outdoorunitconnectingcordsshallnotbelighterthanpolychloroprenesheathedexiblecord.(Design60245IEC57)
Indoorunitpowersupplycordsshallnotbelighterthanpolychloroprenesheathedexiblecord.(Design60227IEC53)

3. Install an earth longer than other cables.

4.Pleasekeepenoughoutputcapacityofpowersupplyforeachheater.Insufcientpowersupplycapacitymightcausechattering.

*1 If the installed earth leakage circuit breaker

does not have an over-current protection

function, install a breaker with that function
along the same power line.

Afx label A that is included with the manuals near each
wiring diagram for cylinder unit and outdoor units.

OCH570

S1

S2

S3

L

N

L

N

CN01

CN01

CN01

CN01

S1

S2

S3

L

N

S1

S2

S3

S1

S2

S3

TB1

L

N

L

N

ECB1

ECB2

L

N

19

Initial settings
(Power supplied by

outdoor unit)

Modied settings
(Separate power

supply to the cylinder
unit)

Cylinder unit
control board

Cylinder unit
control board

White

BLACK

BLACK

YELLOW

BLACK

YELLOW

YELLOW

YELLOW

BLACK

White

Option 2: Cylinder unit powered by independent source.

If the cylinder unit and outdoor unit have separate power supplies, the following

requirements MUST be carried out:

•Changetheinterconnectedwiringin thecontroland electricalboxofthe

cylinder unit (see Figure 7-3).

•TurntheoutdoorunitDIPswitchSW8-3toON.

•TurnontheoutdoorunitBEFOREthecylinderunit.

•Powerbyindependentsourceisnotavailableforparticularmodelsof

outdoor unit model. For more detail, refer to the connecting outdoor unit
Installation Manual.

Wiring

circuit

breaker

or

Isolating

switch

Power

supply
~/N
230 V

50 Hz

Earth

leakage

circuit

breaker

*1

Earth

leakage

circuit

breaker

*1

Wiring

circuit

breaker

or

Isolating

switch

Power

supply
~/N
230 V

50 Hz

Outdoor unit

Cylinder unit

Power

supply
~/N
230 V

50 Hz

Power

supply
~/N
230 V

50 Hz

Wiring

circuit

breaker

or

Isolating

switch

Wiring

circuit

breaker

or

Isolating

switch

For
booster
heater
(Primary circuit)

For
Immersion
heater
(DHW tank)

To control
board

<1 phase>

<Figure 7-4>

Electrical connections 1 phase

<Figure 7-3>

Description Power supply Capacity Breaker Wiring

Booster heater (Primary circuit) ~/N 230 V 50 Hz 2 kW 16 A *1 2.5 mm²

6 kW 32 A *1 6.0 mm²

Immersion heater (DHW tank) ~/N 230 V 50 Hz 3 kW 16 A *1 2.5 mm²

Cylinder unit power supply ~/N 230 V 50 Hz

Cylinder unit input capacity

Main switch (Breaker)

*1

16 A

Wiring

Wiring No.

× size (mm²)

Cylinder unit power supply 2 × Min. 1.5
Cylinder unit power supply earth 1 × Min. 1.5

Cylinder unit - Outdoor unit *2 2 × Min. 0.3
Cylinder unit - Outdoor unit earth —

Circuit

rating

Cylinder unit L - N *3 230 V AC
Cylinder unit - Outdoor unit S1 - S2 *3 —
Cylinder unit - Outdoor unit S2 - S3 *3 24 V DC

*1. A breaker with at least 3.0 mm contact separation in each pole shall be provided. Use earth leakage breaker (NV).

The breaker shall be provided to ensure disconnection of all active phase conductors of the supply.

*2. Max. 120 m
*3. The values given in the table above are not always measured against the ground value.

Note: 1. Wiring size must comply with the applicable local and national codes.

2.Indoorunit/outdoorunitconnectingcordsshallnotbelighterthanpolychloroprenesheathedexiblecord.(Design60245IEC57)
Indoorunitpowersupplycordsshallnotbelighterthanpolychloroprenesheathedexiblecord.(Design60227IEC53)

3. Install an earth longer than other cables.

4.

Please keep enough output capacity of power supply for each heater.

Insufcientpowersupplycapacitymightcausechattering.

*1 If the installed earth leakage circuit breaker

does not have an over-current protection

function, install a breaker with that function
along the same power line.

Affix label B that is included with the manuals near
each wiring diagram for cylinder unit and outdoor units.

OCH570

L1

L2

S1

S2

S3

S1

S2

S3

TB1

L2

L3

ECB1

ECB2

N

L3

L1

L

N

L

N

20

<3 phase>

<Figure 7-5>

Electrical connections 3 phase

Description Power supply Capacity (Indoor unit Ref.) Breaker Wiring

Booster heater (Primary circuit)

3~ 400 V 50 Hz 9 kW 16 A *1 2.5 mm²
3~ 230 V 50 Hz 9 kW 32 A *1 6.0 mm²

Immersion heater (DHW tank) ~/N 230 V 50 Hz 3 kW 16 A *1 2.5 mm²

Cylinder unit power supply ~/N 230 V 50 Hz

Cylinder unit input capacity

Main switch (Breaker)

*1

16 A

Wiring

Wiring No.

× size (mm²)

Cylinder unit power supply 2 × Min. 1.5
Cylinder unit power supply earth 1 × Min. 1.5

Cylinder unit - Outdoor unit *2 2 × Min. 0.3
Cylinder unit - Outdoor unit earth —

Circuit

rating

Cylinder unit L - N *3 230 V AC
Cylinder unit - Outdoor unit S1 - S2 *3 —
Cylinder unit - Outdoor unit S2 - S3 *3 24 V DC

*1. A breaker with at least 3.0 mm contact separation in each pole shall be provided. Use earth leakage breaker (NV).

The breaker shall be provided to ensure disconnection of all active phase conductors of the supply.

*2. Max. 120 m
*3. The values given in the table above are not always measured against the ground value.

Note: 1. Wiring size must comply with the applicable local and national codes.

2.Indoorunit/outdoorunitconnectingcordsshallnotbelighterthanpolychloroprenesheathedexiblecord.(Design60245IEC57)
Indoorunitpowersupplycordsshallnotbelighterthanpolychloroprenesheathedexiblecord.(Design60227IEC53)

3. Install an earth longer than other cables.

4.Pleasekeepenoughoutputcapacityofpowersupplyforeachheater.Insufcientpowersupplycapacitymightcausechattering.

For
booster
heater
(Primary circuit)

For
Immersion
heater
(DHW tank)

To control
board

*1 If the installed earth leakage circuit breaker

does not have an over-current protection

function, install a breaker with that function
along the same power line.

Affix label B that is included with the manuals near
each wiring diagram for cylinder unit and outdoor units.

Wiring

circuit

breaker

or

Isolating

switch

Power

supply
3N~
400 V

50 Hz

Earth

leakage

circuit

breaker

*1

Wiring

circuit

breaker

or

Isolating

switch

Earth

leakage

circuit

breaker

*1

Power

supply
~/N
230 V

50 Hz

Power

supply
~/N
230 V

50 Hz

Outdoor unit

Cylinder unit

Wiring

circuit

breaker

or

Isolating

switch

Wiring

circuit

breaker

or

Isolating

switch

Power supply

3~ 400 V 50 Hz (EH*T20*-YM*C)
3~ 230 V 50 Hz (EH*T20*-TM*C)

OCH570

11

8

27

19

20

18

17

3

4

25

28

7

12

26

5

15

13

29

23

14

6

7

24

Pa

10

9

B

A

30

32

32

33

31

31

30

22

*1

Pa

11

10

8

27

19

9

16

20

B

A

30

*1

32

33

18

17

30

30

35

37

21

3

4

25

28

7

5

15

13

29

23

32

14

6

7

24

36

12

26

21

WATER SYSTEM DIAGRAM

8

• Refer to <Table 4-1> for the part names.
*1 Refer to the following section [Local system].

<EHST20*-*M**C > (Split model system)

<EHST20*-MHCW> (UK Split model system) <Example>

<Figure 8-2>

<Figure 8-1>

Note

• To enable draining of the cylinder unit
an isolating valve should be posi-

tioned on both the inlet and outlet

pipework.

• Be sure to install a strainer on the inlet
pipework to the cylinder unit.

• Suitable drain pipework should be at-

tached to all relief valves in accord-

ance with your country’s regulations.

• A backow prevention device must be
installed on the cold water supply
pipework (IEC 61770)

• When using components made from
different metals or connecting pipes

made of different metals insulate the

joints to prevent any corrosive reac­tion taking place which may damage
the pipework.

Flare connection

Flare connection

Cylinder unit

Cylinder unit

Drain

Drain

Drain

Drain

Drain

Drain

Cold water

Cold water

DHW

DHW

Local system

Refrigerant pipe

Water pipe

Local system

Flexible hose

(Temporary connection)

Water
supply

Note

•

To enable draining of the cylinder unit
an isolating valve should be positioned
on both the inlet and outlet pipework.
No valve should be tted between the
expansion valve (item 35) and the cyl-

inder unit (safety matter).

• Be sure to install a strainer on the inlet

pipework to the cylinder unit.

• Suitable drain pipework should be at-

tached to all relief valves in accord-

ance with your country’s regulations.

• When using components made from

different metals or connecting pipes

made of different metals insulate the

joints to prevent any corrosive reac­tion taking place which may damage
any pipework.

• Filling loop’s exible hose must be re-

moved following the lling procedure.
Item provided with unit as loose ac-

cessory.

• Install the inlet control group (item 33)

above the level of the T&P relief valve
(item 19). This will ensure DHW tank
will not require drain-down to service/
maintain the inlet control group.

Refrigerant pipe

Water pipe

OCH570

10

9

30

*1

32

32

33

34

B

30

30

35

A

Pa

11

8

27

19

16

20

18

17

21

37

3

7

13

29

36

32

34

32

4

25

5

23

6

7

24

15

14

7

12

26

1

10

27

9

30

32

32

34

34

32

B

31

A

31

32

33

Pa

11

4

25

8

27

7

19

5

15

13

16

23

20

14

6

7

24

18

17

*1

7

30

22

12

26

22

<EHPT20X-MHCW> (UK Packaged model system) <Example>

Note

• To enable draining of the cylinder unit an
isolating valve should be positioned on
both the inlet and outlet pipework. No
valve should be fitted between the ex-

pansion valve (item 35) and the cylinder
unit (safety matter).

• Be sure to install a strainer on the inlet
pipework to the cylinder unit.

• Suitable drain pipework should be at-

tached to all relief valves in accordance

with your country’s regulations.

• When using components made from dif­ferent metals or connecting pipes made
of different metals insulate the joints to
prevent any corrosive reaction taking
place which may damage any pipework.

• Filling loop’s flexible hose must be re­moved following the filling procedure.
Item provided with unit as loose acces-

sory.

• Install the inlet control group (item 33)
above the level of the T&P relief valve
(item 19). This will ensure DHW tank
will not require drain-down to service/
maintain the inlet control group.

Model name EHPT20X-MHCW EHST20C-MHCW EHST20D-MHCW

Maximum supply pressure to the pressure reducing valve 16 bar 16 bar 16 bar
Operating pressure (Potable side) 3.5 bar 3.5 bar 3.5 bar
Expansion vessel charge setting pressure (Potable side) 3.5 bar 3.5 bar 3.5 bar
Expansion valve setting pressure (Potable side) 6.0 bar 6.0 bar 6.0 bar
Immersion heater specication (Potable side) * 3000 W, 230 V 3000 W, 230 V 3000 W, 230 V

DHW tank capacity 200 L 200 L 200 L

Mass of the unit when full 307 kg 320 kg 312 kg
Maximum primary working pressure 2.5 bar 2.5 bar 2.5 bar

* EN60335/Type 3000W single phase 230V 50Hz, length 460 mm.

Use only Mitsubishi Electric service parts as a direct replacement.

<Table 8-1>

<EHPT20X-*M*C> (Packaged model system)

Note

• To enable draining of the cylinder
unit an isolating valve should be po-

sitioned on both the inlet and outlet

pipework.

• Be sure to install a strainer on the inlet
pipework to the cylinder unit.

• Suitable drain pipework should be

attached to all relief valves in accord-

ance with your country’s regulations.

• A backflow prevention device must
be installed on the cold water supply
pipework (IEC 61770)

• When using components made from
different metals or connecting pipes

made of different metals insulate the

joints to prevent any corrosive reac­tion taking place which may damage
the pipework.)

<Figure 8-3>

<Figure 8-4>

Cylinder unit

Drain

Drain

Drain

Drain

Cold water

DHW

Local system

Main water supply

Flexible hose

(Temporary connection)

Cylinder unit

Drain

Drain

Cold water

DHW

Local system

Water
supply

Water pipe

Water pipe

• Refer to <Table 4-1> for the part names.
*1 Refer to the following section [Local system].

OCH570

1-zone temperature control

2-zone temperature control 1-zone temperature control with boiler

2-zone temperature control with boiler

1-zone temperature control (2-zone valve ON/OFF control)

23

Local system

3

7

5

2

4

6

8

9

11

1

12

10

Zone1

Zone2

1

2

3

5

6

4

Zone1

1

5

4

3

6

2

13

14

15

Zone1

2

13

14

15

7

5

4

3

6

1

8

9

11

12

10

Zone1

Zone2

* Flow switch specications: DC12 V / 1 mA / Both normally-open and normally-closed types can be used. (Set DIP switch 3 to select the logics. Refer to “6-7. DIP

switch setting”.)

1. Zone1 heat emitters (e.g. radiator, fan coil unit) (local supply)

2. Mixing tank (local supply)

3. Zone1 ow water temp. thermistor (THW6)

4. Zone1 return water temp. thermistor (THW7)

5. Zone1 water circulation pump (local supply)

6. Zone1 ow switch (local supply) *

7. Motorized mixing valve (local supply)

8. Zone2 ow water temp. thermistor (THW8)

9. Zone2 return water temp. thermistor (THW9)

Optional part : PAC-TH011-E

Optional part : PAC-TH011-E

10. Zone2 water circulation pump (local supply)

11. Zone2 ow switch (local supply) *

12. Zone2 heat emitters (e.g. underoor heating) (local supply)

13. Boiler ow water temp. thermistor (THWB1)

14. Boiler return water temp. thermistor (THWB2)

15. Boiler (local supply)

16. Zone1 2-way valve (local supply)

17. Zone2 2-way valve (local supply)

18. Bypass valve (local supply)

Optional part : PAC-TH011HT-E

1

Zone1

16

18

Zone1

Zone2

17

12

1

OCH570

24

Filling the cylinder unit (Primary circuit)

Draining the cylinder unit

WARNING: DRAINED WATER MAY BE VERY HOT

1. Before attempting to drain the cylinder unit isolate from the electrical supply to prevent the immersion and booster heaters burning out.

2. Isolate cold water feed to DHW tank.

3. Attach a hose to the DHW tank drain cock (No. 23 and 24 on Figure 4-1). The hose should be able to withstand heat as the draining water could be very hot. The
hose should drain to a place lower than the DHW tank bottom to encourage siphoning.
Open a hot water tap to start draining without a vacuum.

4. When the DHW tank is drained close drain cock and hot tap.

5. Attach hose to water circuit drain cock (No. 7 on Figure 4-1). The hose should be able to withstand heat as the draining water could be very hot. The hose should
drain to a place lower than the booster heater drain cock to encourage siphoning. Open the pump valve and the strainer valve.

6. Water remains in the strainer still after the cylinder unit was drained.
Drain the strainer by removing the strainer cover.

Initial ll procedure:

1. Ensure all pipe joints and ttings are tight and secure.

2. Open the most distant DHW tap/outlet.

3. Slowly/gradually open the mains water supply to begin lling unit and DHW pipework.

4. Allow most distant tap to run free and release/purge residual air from installation.

5. Close tap/outlet to retain fully charged system.

Initial ush procedure:

1. Energise system to heat-up cylinder contents to a temperature of approx. 30 – 40°C.

2. Flush/drain the water contents to remove any residue/impurities resulting from the installation works. Use the cylinder drain cock to safely discharge the warmed
water to drain via a suitable hose.

3. On completion, close drain cock, re-ll system and resume system commissioning.

Filling the cylinder unit (Potable/DHW circuit)

1. Check all connections including factory tted ones are tight.

2. Insulate pipework between cylinder unit and outdoor unit.

3.

Thoroughly clean and ush, system of all debris. (

Refer to 4.2 in the installation manual.)

4. Fill cylinder unit with potable water. Fill primary heating circuit with water and suitable anti-freeze and inhibitor as necessary. Alwaysuseallingloopwith

doublecheckvalvewhenllingtheprimarycircuittoavoidbackowcontaminationofwatersupply.

• Anti-freeze should always be used for packaged model systems. It is the responsibility of the installer to decide if anti-freeze solution should be used in split
model systems depending on each site’s conditions. Corrosion inhibitor should be used in both split model and packaged model systems.

• When connecting metal pipes of different materials insulate the joints to prevent a corrosive reaction taking place which will damage the pipework.

5. Check for leakages. If leakage is found, retighten the nut onto the connections.

6. Pressurise system to 1 bar.

7. Release all trapped air using air vents during and following heating period.

8. Top up with water as necessary. (If pressure is below 1 bar)

OCH570

F1 F2 F3 F4

25

CONTROLS

9

B C D

E

A

Main screen

9-1. Main Controller

<Main controller parts>

Let­ter

Name Function

A Screen Screen in which all information is displayed

B Menu Access to system settings for initial set up and

modications.

C Back Return to previous menu.
D Conrm Used to select or save. (Enter key)
E Power/Holiday If system is switched off pressing once will turn

system on. Pressing again when system is
switched on will enable Holiday Mode. Holding
the button down for 3 secs will turn the system

off. (*1)

F1-4 Function keys Used to scroll through menu and adjust settings.

Function is determined by the menu screen
visible on screen A.

*1
When the system is switched off or the power supply is disconnected,
the cylinder unit protection functions (e.g. freeze stat. function) will
NOT operate. Please beware that without these safety functions ena­bled the cylinder unit may potentially become exposed to damage.

<Main screen icons>

Icon Description

1 Legionella

prevention

When this icon is displayed ‘Legionella prevention
mode’ is active.

2 Heat pump

‘Heat pump’ is running.

Defrosting

Emergency heating

3 Electric heater When this icon is displayed the ‘Electric heaters’

(booster or immersion heater) are in use.

4 Target

temperature

Target ow temperature

Target room temperature

Compensation curve

5 OPTION Pressing the function button below this icon will

display the option screen.
6 + Increase desired temperature.
7 - Decrease desired temperature.
8 Z1

Z2 Pressing the function button below this icon

switches between Zone1 and Zone2.

Information Pressing the function button below this icon dis-

plays the information screen.
9 Space heating

mode

Heating mode

Zone1 or Zone2
10 DHW mode Normal or ECO mode
11 Holiday mode

When this icon is displayed ‘Holiday mode’ acti­vated.

12 Timer

Prohibited

Server control

Stand-by

Stand-by (*2)

Stop

Operating

13

Current
temperature

Current room temperature

Current water temperature of DHW tank

14

The Menu button is locked or the switching of the
operation modes between DHW and Heating op-

erations are disabled in the Option screen.(*3)

15

SD memory card is inserted. Normal operation.

SD memory card is inserted. Abnormal operation.

*2 This unit is in Stand-by whilst other indoor unit(s) is in operation

by priority.

*3 To lock or unlock the Menu, press the BACK and CONFIRM keys

simultaneously for 3 seconds.

12 11

1 32

10

9

4

7

6

5

15 14

13

8

OCH570

26

9-2. Setting the Main Controller

After the power has been connected to the outdoor and cylinder units (See chapter 7) the initial system settings can be entered via the main controller.

1. Check all breakers and other safety devices are correctly installed and turn on power to the system.

2. When the main controller switched on for the rst time, the screen automatically goes to Initial settings menu, Language setting screen and Date/Time setting

screen in order.

3. Main controller will automatically start up. Wait approximately 6 minutes whilst the control menus load.

4. When the controller is ready a blank screen with a line running across the top will be displayed.

5. Press button E (Power) (refer to page 25) to turn on the system. Before turning on the system, perform initial settings as instructed below.

General Operation

● To nd the icon that you wish to set, use the F2 and F3 buttons to move between the icons.

● The highlighted icon will appear as a larger version of the center of the screen.

● Press CONFIRM to select and edit the highlighted mode.

●

Follow the <Main Controller Menu Tree> for further setting, using ▼▼ buttons for scrolling or F1 to F4 for selecting.

9-3. Main Settings Menu

The main settings menu can be accessed by pressing the MENU button. To re­duce the risk of untrained end users altering the settings accidentally there are
two access levels to the main settings; and the service section menu is password

protected.

User Level – Short press

If the MENU button is pressed once for a short time the main settings will be
displayed but without the edit function. This will enable the user to view current
settings but NOT change the parameters.

Installer Level – Long press

If the MENU button is pressed down for 3 secs the main settings will be displayed
with all functionality available.

The following items can be viewed and/or edited (dependent on access level).

• Domestic Hot water (DHW)

• Heating

• Schedule timer

• Holiday mode

• Initial settings

• Service (Password protected)

Main menu

Long Press

OCH570

27

<Main Controller Menu Tree>

Unrestricted access
Installer only

* Short press for 1 Zone system.

*

Main

menu

Main

menu

Main screen

Initial

Information

Option

F1

F4

Forced DHW

Hot Water (DHW)

<See section>

<See

section>

<See

section>

<See

section>

<See

section>

Menu

Long Press

Short Press

Heating

Holiday

mode

Initial

settings

Schedule timer

(Zone1)

(Zone2)

(

PREVIEW

)

(

EDIT

)

(

EDIT

)

(

EDIT

)

(

EDIT

)

DHW

DHW

Legionella

Legionella

Schedule2 period

preview screen

Schedule2 period setting screen1

Term setting

Schedule1/2 select

F4

Schedule

timer preview

F4

Schedule

timer preview

F4

Schedule timer preview

F4

Schedule timer preview

Zone1

Zone1

Zone2

Curve parameters

Curve parameters

Adjustment

Adjustment

Zone1

Zone2

Zone2

Day
select

Day
select

Day
select

Day
select

Day
select

Day
select

Time select

Time select

Time select

Time select

Time select

Time select

Temp.setting

Temp.setting

Temp.setting

Temp.setting

Schedule1

Schedule2

Heating

Heating

DHW

DHW

ON (

)/OFF

DHW ON (

)/Prohibited ( )/Timer ( )

Heating ON (

)/Prohibited ( )/Timer ( )

Consumed electrical energy

Delivered energy

Normal/Eco

DHW max. temp.

Hot water temp.

Frequency
Start time

Max. operation time
Duration of max. temp.

DHW max. temp. drop
DHW max. operation time

DHW mode restriction

Active/Non active

Room temp.(

) / Flow temp.(

)

/ Compensation curve(

)

Room temp.(

) / Flow temp.(

)

/ Compensation curve(

)

Compensation curve preview

Compensation curve edit

F1

F1

F3

F1

F2

F2

F2

F2 F4

F3

F3

F3

F4

F4

F3

F4

F2

F4

F3

F4

F2

F3

F4

DHW

Date/Time yyyy/mm/dd/hh:mm

EN/FR/DE/SV/ES/IT/DA/NL/FI/NO/PT/BG/PL/CS/RU

OFF/Room/Tank/Room&Tank

OFF/ON

hh:mm/hh:mm AM/AM hh:mm

°C/°F

Room RC zone select

Sensor setting

Zone1

Zone1

Zone2

Holiday mode setting

Heating room temp.

Heating room temp.

Heating ow temp.

Heating ow temp.

Zone2

Sensor setting

Sensor setting

Select Time/Zone

Select Time/Zone

TH1/Main controller/
Room RC1-8/ “Time/
Zone”

TH1/Main controller/
Room RC1-8/ “Time/
Zone”

Time setting

Time setting

Sensor setting

Sensor setting

Language

Summer time

Temp. display

Contact number

Time display

°C/°F

Room sensor settings

Heating

Active/Non active
Active/Non active

Long press

(

EDIT

)

F1 F2

Zone1/2 select

F1 F2

Zone1/2 select

<Continued to next page.>

F1

Zone1/2 select

F1

Zone1/2 select

F1 F2

Zone1/2 select

save

save

save

save

save

save

save

F4

Schedule

timer preview

F4

Schedule

timer preview

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28

<Continued from the previous page.>

<Main Controller Menu Tree>

Unrestricted access
Installer only

Main screen

Initial

Main
menu

Service

Password

protected

Manual operation

Function settings
Thermistor adjustment

Economy settings for pump

Electric heater (Heating)

Electric heater (DHW)

Mixing valve control

Flow sensor

Standard (Heat pump & electric heater)/Heater (Electric heater only)/
Boiler/Hybrid (Heat pump & heater/Boiler)

Freeze stat function

Simultaneous operation

Cold weather function

Boiler settings *1

Energy monitor
setting

External input settings

Running information

Thermistor reading

Summary of settings

Error history

Password protection

Manual reset

SD card

Heating

operation

H/P thermo diff.adjust

Flow temp.range

Room temp.control

Auxiliary settings

Heat source setting

Pump speed

Operation settings

ON/OFF
Delay

ON/OFF
Delay

Running

Interval

Flow t.

Ambient

ON/OFF
Ambient

ON/OFF

Hybrid

settings

Ambient

Energy

price

CO

2

emission

Heat source

Schedule

Electricity

Electricity

Heat pump capacity

ON/OFF

Electric heater
capacity

Demand control (IN4)

Main controller

SD

Yes/No

Select download data

OFF (Heat source)/Boiler

Heater/Boiler

Outdoor thermostat (IN5)

FTC

Main RC SD

Yes/No

Select upload data

Water pump input

Electric energy meter

Booster heater 1 capacity

Pump 1

Booster heater 2 capacity

Pump 2

Immersion heater

Pump 3

Boiler

Boiler

Boiler efciency

Target temp.

Start & Finish

Temp. increase step

Temp. decrease step

Max. temp.
Max. temp. period

Increase interval

Decrease interval

Booster heater 2
capacity

Booster heater 1
capacity

Flow temp.

(Increase)

Flow temp.

(Decrease)

Priority Ambient/

Cost /CO

2

Ambient

Intelligent
settings

Min.temp.

ON/OFF

Mode
Interval

Max.temp.

Lower

Upper

Minimum

Maximum

ON/OFF
Delay

(Booster heater/Immersion heater)

*1 For more details, refer to the installation manual of PAC-TH011HT-E.

Floor dry up function

For more details,

refer to Page 32.

(

(

<See section>

F1 F2 F3

Menu

Long Press

Delivered energy adjustment

Heat meter

Main RC

Long press

OCH570

29

Manual operation menu screen

The service menu provides functions for use by installer or service engineer. It is NOT intended the home owner alters settings within this menu. It is for this reason
password protection is required to prevent unauthorised access to the service settings.

The factory default password is "0000".
Follow the procedure described in General Operation for the set up operation.

The service menu is navigated using the F1 and F2 buttons to scroll
through the functions. The menu is split across two screens and is
comprised of the following functions;

1. Manual operation

2. Function settings

3. Thermistor adjustment

4. Auxiliary settings

5. Heat source setting

6. Pump speed

7. Operation settings

8. Energy monitor settings

9. External input settings

10. Running information

11. Thermistor reading

12. Summary of settings

13. Error history

14. Password protection

15. Manual reset

16. SD card

9-4. Service Menu

Many functions can not be set whilst the indoor unit is running. The installer should turn off the unit before trying to set these functions. If the installer attempts to

change the settings whilst the unit is running the main controller will display a reminder message prompting the installer to stop operation before continuing. By
selecting “Yes” the unit will cease operation.

Being

selected

Being running Error

indication

<Manual operation>

During the lling of the system the water circulation pump and 3-way valve
can be manually overridden using manual operation mode.

When manual operation is selected a small timer icon appears in the screen.

The function selected will only remain in manual operation for a maximum of 2

hours. This is to prevent accidental permanent override of the FTC.

►Example
Pressing F3 button will switch manual operation mode ON for the main 3-way
valve. When lling of the DHW tank is complete the installer should access this
menu again and press F3 to deactivate manual operation of the part.
Alternatively after 2 hours manual operation mode will no longer be active and
FTC will resume control of the part.

Manual operation and heat source setting can not be selected if the system
is running. A screen will be displayed asking the installer to stop the system

before these modes can be activated.
The system automatically stops 2 hours after last operation.

<Function settings>

Function Setting allows the setting of auto recovery after power failure only.

1. From the service menu use F1 and F2 to highlight Function Setting.

2. Press CONFIRM.

3. Ensure the Ref address and unit number are displayed to the right.

4. Press CONFIRM.

5. Use F3 and F4 to highlight either 1/2/3 (see below).
Note: Changes can ONLY be made to Mode 1.

6. Press CONFIRM.

Mode 1 Setting number meanings
1 - Power failure automatic recovery NOT available
2 - Power failure automatic recovery AVAILABLE

(Approx 4-minute delay after power is restored.)

3 - NO FUNCTION

OCH570

▼

▲

30

Thermistor adjustment

This function allows adjustments to be made to the thermistor readings from

-10 – 10 °C in 0.5 °C intervals.

1. From the Service menu highlight Thermistor Adjustment

2. Press CONFIRM.

3. Use F1 and F2 to select thermistor.

4. Press CONFIRM.

5. Use F2 and F3 to change the thermistor temperature.

6. Press CONFIRM.

Auxiliary settings menu screen

<Auxiliary settings>

This function is used to set the parameters for any auxiliary parts used in the system

Menu subtitle Function/ Description

Economy settings for

pump

Water pump stops automatically in certain period of time from

when operation is nished.

Delay Time before pump switched off*1

Electric heater

(Heating)

To select “WITH booster heater (ON)” or “WITHOUT booster

heater (OFF)” in Heating mode.

Delay The minimum time required for the booster heater to turn ON

from after Heating mode has started.

Electric heater (DHW) To select "WITH (ON)" or "WITHOUT (OFF)" booster heater or

immersion heater individually in DHW mode.

Delay The minimum time required for the booster heater or immersion

heater to turn ON from after DHW mode has started. (This

setting is applied for both booster and immersion heater.)

Mixing

valve
control *2

Running Period from valve fully open (at a hot water mixing ratio of 100%)

to valve fully closed (at a cold water mixing ratio of 100%)

Interval Interval (min) to control the Mixing valve.

Flow

sensor *3

Minimum The minimum ow rate to be detected at Flow sensor.

Maximum The maximum ow rate to be detected at Flow sensor.

*1. Decreasing "time before pump switched off" may increase the duration of stand-by in

Heating/Cooling mode.

*2.

Set the Running time according to the specications of the actuator of each mixing valve.

It is recommended to set the interval to 2 minutes that is a default value. With the interval

set longer, it could take longer to warm up a room.

*3.

Do not change the setting since it is set according to the specication of Flow sensor

attached to the cylinder unit.

Economy settings for pump

1. From the Auxiliary settings menu highlight Economy Settings for water circulation pump.

2. Press CONFIRM.

3. The economy settings for water circulation pump screen is displayed.

4. Use button F1 to switch the economy settings ON/OFF.

5. Use buttons F3 and F4 to adjust the time the water circulation pump will run. (3 - 60

minutes)

Electric heater (Heating)

1. From the Auxiliary settings menu highlight Electric heater (Heating).

2. Press CONFIRM.

3. The Electric heater (Heating) screen is displayed.

4. Press F1 button to switch the function ON/OFF.

5. Use F3 and F4 buttons to adjust the time period of heat pump only operation
before the booster heater will assist in space heating. (5 -180minutes)

Electric heater (DHW)

1. From the Auxiliary settings menu highlight Electric heater (DHW).

2. Press CONFIRM.

3. The Electric heater (DHW) screen is displayed.

4. Press F1 and F2 buttons to switch the function ON/OFF. (F1: booster heater,

F2: immersion heater)

5. Use F3 and F4 buttons to adjust the time period of heat pump only operation
before the booster heater and the immersion heater (if present) will assist in
DHW heating. (15 -30minutes)

Electric heater (Heating) screen

Electric heater (DHW) screen

Economy settings for pump screen

OCH570

Mixing valve setting screen

Pump speed setting screen

Heat source setting screen

Flow sensor setting screen

31

Mixing valve control

1. From the Auxiliary settings menu highlight Mixing valve control.

2. Press CONFIRM.

3. The Mixing valve control screen is displayed.

4. Use F1 and F2 buttons to set Running time between 10 to 240 seconds. The
Running time equals to a period from full open of the valve (at a hot water
mixing ratio of 100%) to full close (at a cold water mixing ratio of 100%).

Note: Set the Running time according to the specifications of the actuator

of each mixing valve.

1. From the Auxiliary settings menu highlight Mixing valve control.

2. Press CONFIRM.

3. The Mixing valve control screen is displayed.

4. Press F3 and F4 buttons to set the interval between 2-zone temperature
controls of the mixing valve between 1 to 30 minutes.

Note: It is recommended to set the interval to 2 minutes that is a default

value. With the interval set longer, it could take longer to warm up a
room.

<Pump speed>

1. From the Service menu highlight water pump speed.

2. Press CONFIRM.

3. Press F3 and F4 buttons to select a refrigerant address of which you wish to
congure or check the settings, and press CONFIRM. *1

4. The Pump speed screen is displayed.

5. Use F2 and F3 buttons to set the pump speed of the water circulation pump
between 1 and 5.

*1 For multiple outdoor units control system only.

<Heat source setting>

The default heat source setting is heat pump and all electric heaters present in

the system to be operational. This is referred to as Standard operation on the
menu.

Flow sensor

1. From the Auxiliary settings menu highlight Flow sensor.

2. Press CONFIRM.

3. Press F3 or F4 buttons to select a refrigerant address of which you wish to
congure or check the settings, and press CONFIRM. *1.

4. The Flow sensor screen is displayed.

5. Use F1 and F2 buttons to set the minimum ow rate of ow sensor between 0
to maximum L/min.

6. Use F1 and F2 buttons to set the maximum ow rate of ow sensor between

minimum to 100L/min.

*1 For multiple outdoor units control system only.

Note: Do not change the setting since it is set according to the

specification of Flow sensor attached to the cylinder unit.

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32

<Operation settings>

Freeze stat function

Menu subtitle Function/ Description

Freeze stat function An operational function to prevent the water circuit from freezing when outdoor ambient temperature drops.

Flow t. The target outlet water temperature at water circuit when operating in Freeze stat function. *2

Outdoor ambient temp. Minimum outdoor ambient temperature which freeze stat function will begin to operate,

(3 - 20ºC) or choose**. If asterisk (**) is chosen freeze stat function is deactivated. (i.e. primary water freeze risk)"

*1. When the system is turned off, freeze stat function is not enabled.
*2. Flow t. is xed to 20°C and unchangeable.

Simultaneous Operation

For periods of very low outside temperature this mode can be used. Simultaneous
operation allows both DHW and space heating to run together by using the heat pump
and/or booster heater to provide space heating whilst only the immersion heater
provides heating for DHW. This operation is only available if BOTH a DHW tank AND

immersion heater are present on the system.

Heating operation

This function allows operational setting of ow temperature range from the Ecodan and also the time interval at which the FTC collects and processes data for the auto

adaptation mode.

Menu subtitle Function Range Unit Default
Flow temp. range Minimum temp. To minimize the loss by frequent ON and OFF in mild outdoor ambient tem-

perature seasons.

25 - 45 ºC 30

Maximum temp. To set max. possible ow temperature according to the type of heat emitters. 35 - 60 ºC 50

Room temp. control Mode Setting for Room temp. control

At Fast mode, target outlet water temperature is set higher than the one set
at normal mode. This reduces the time to reach the target room temperature
when the room temperature is relatively low.*3

Normal/
Fast

-- Normal

Interval Selectable according to the heat emitter type and the materials of oor (i.e.

radiators, oor heating-thick, -thin concrete, wood, etc.)

10 ~ 60

minutes

10

Heat pump thermo diff.adjust On/Off To minimize the loss by frequent ON and OFF in mild outdoor ambient tem-

perature seasons.

On/Off — On

Lower limit Prohibits heat pump operation until the flow temperature drops below the

target ow temperature plus lower limit value.

−9 - −1 ºC −5

Upper limit Allows heat pump operation until the ow temperature rises above the target

ow temperature plus upper limit value.

+3 - +5 ºC +5

< Heating operation (Room temp. control table) >

Note:

1. The minimum ow temperature that prohibits heat pump operation is 20ºC.

2. The maximum ow temperature that allows heat pump operation equals to the maximum temperature set in the Flow temp. range menu.

* Fast mode is not efcient and will increase running cost compared to normal mode.

• Range of outdoor ambient temperature at which simultaneous
operation starts is −30°C to 10°C (default −15°C).

• System shall automatically return to routine operation. This will
happen when the outdoor ambient temperature rises above the
selected temperature for this specic mode of operation.

Cold weather function

For extremely low outdoor ambient temperature conditions when the heat pump’s capacity is restricted the heating or DHW is provided only by the electric booster
heater (and immersion if present). This function is intended for use during extreme cold periods only. Extensive use of direct electrical heaters ONLY will result in
higher power consumption and may reduce working life of heaters and related parts.

Floor dry up function

The Floor dry up function automatically changes the target hot water temperature
in stages to gradually dry concrete when this particular type of underoor heating

system is installed.

Upon completion of the operation the system stops all the operations except the

Freeze stat. operation.

For Floor dry up function, the target ow temp. of Zone 1 is the same as that of

Zone 2.

Functions Symbol Description Option/Range Unit Default

Floor dry up function a

Set the function to ON and power on the system using the main controller,
and the dry up heating operation will start.

On/Off — Off

Flow temp.

(increase)

Flow temp. increase step b Sets the increase step of the target ow temperature. +1 - +10 ºC +5
Increase interval c Sets the period for which the same target ow temperature is maintained. 1 - 7 day 2

Flow temp.

(decrease)

Flow temp. decrease step d Sets the decrease step of the target ow temperature. −1 - −10 ºC −5
Decrease interval e Sets the period for which the same target ow temperature is maintained. 1 - 7 day 2

Target

temperature

Start & Finish f Sets the target ow temperature at the start and the nish of the operation. 25 - 60 ºC 30
Max. target temp. g Sets the maximum target ow temperature. 25 - 60 ºC 45

Max. temp. period h

Sets the period for which the maximum target ow temperature is main-

tained.

1 - 20 day 5

45

40

35

30

0 1 2 3 4 5 6 7 8 9 10 11 12 1314 15 16 17 18

(

°C

)

(b)

(d)

(h)

(c)

(f)

(e)

(g)

Days

Target ow temp.

• This function is not available when a PUHZ-FRP outdoor unit is connected.

• Disconnect wiring to external inputs of room thermostat, demand control, and
outdoor thermostat, or the target ow temperature may not be maintained.

• Range of outdoor ambient temperature at which cold weather function starts
is −30°C to −10°C (default −15°C).

• System shall automatically return to routine operation. This will happen when

the outdoor ambient temperature rises above the selected temperature for

this specic mode of operation.

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33

2. Settings using the main controller

In this menu, all parameters required to record the consumed electrical energy and the delivered heat
energy which is displayed on the main controller can be set. The parameters are an electric heater
capacity, supply power of water pump and heat meter pulse.

Follow the procedure described in General Operation for the set up operation.

For Pump 1, *** can be also set besides this setting.
In the case *** is selected, the system acknowledges "factory tted pump" is selected.

Energy monitor settings menu screen

<Energy monitor settings>

1. General description

End user can monitor accumulated*1 ‘Consumed electrical energy’ and ‘Delivered heat energy’ in each operation mode*2 on the main controller.
*1 Monthly and Year to date
*2 - DHW operation

- Space heating

Refer to the menu tree in “9-3. Main Settings Menu” for how to check the energy, and “6-7. DIP switch setting” for the details on DIP-SW setting.
Either one of the following two method is used for monitoring.

Note: The method (1) should be used as a guide. If a certain accuracy is required, the method (2) should be used.

(1) Calculation internally

Electricity consumption is calculated internally based on the energy consumption of outdoor unit, electric heater, water pump(s) and other auxiliaries.
Delivered heat is calculated internally by multiplying delta T (Flow and Return temp.) and flow rate measured by the factory fitted sensors.
Set the electric heater capacity and water pump(s) input according to indoor unit model and specs of additional pump(s) supplied locally. (Refer to the menu tree
in “9-3. Main Settings Menu”)

Booster heater1 Booster heater2

Immersion

heater*1

Pump1*2 Pump2 Pump3

Default 2kW 4kW 0kW

***(factory tted

pump)

0kW 0kW

EHST20C-VM2C 2kW 0kW 0kW ***

When additional pumps supplied locally are

connected as Pump2/3, change setting ac­cording to specs of the pumps.

EHST20C-VM6C 2kW 4kW 0kW ***

EHST20C-YM9C 3kW 6kW 0kW ***

EHST20C-TM9C 3kW 6kW 0kW ***

EHST20C-VM2EC 2kW 0kW 0kW ***

EHST20C-VM6EC 2kW 4kW 0kW ***

EHST20C-YM9EC 3kW 6kW 0kW ***

EHST20C-MEC 0kW 0kW 0kW ***

EHST20D-VM2C 2kW 0kW 0kW ***

EHST20D-MEC 0kW 0kW 0kW ***

EHST20D-MHC 0kW 0kW 3kW ***

EHPT20X-VM2C 2kW 0kW 0kW ***

EHPT20X-VM6C 2kW 4kW 0kW ***

EHPT20X-YM9C 3kW 6kW 0kW ***

EHPT20X-TM9C 3kW 6kW 0kW ***

EHPT20X-MHCW 0kW 0kW 3kW ***

EHST20C-MHCW 0kW 0kW 3kW ***

EHST20D-MHCW 0kW 0kW 3kW ***

*1 Change setting to 3kW when connecting optional immersion heater "PAC-IH03V2-E".
*2 "***" displayed in the energy monitor setting mode means the factory tted pump is connected as Pump 1 so that the input is automatically calculated.

When anti-freeze solution (propylene glycol) is used for primary water circuit, set the delivered energy adjustment if necessary.
For further detail of above, refer to the menu tree in “9-3. Main Settings Menu”.

(2) Actual measurement by external meter (locally supplied)

FTC has external input terminals for 2 ‘Electric energy meters’ and a ‘Heat meter’.
If two ‘Electric energy meters’ are connected, the 2 recorded values will be combined at the FTC and shown on the main controller.
(e.g. Meter 1 for H/P power line, Meter 2 for heater power line)
Refer to the [Signal inputs] in section “6. WIRING DIAGRAM” for more information on connectable electric energy meter and heat meter.

● Connectable electric energy meter and heat meter

▪

Pulse meter type

Voltage free contact for 12VDC detection by FTC (TBI.3 1, 3 and 5 pin have a positive voltage.)

▪

Pulse duration

Minimum ON time: 40ms
Minimum OFF time: 100ms

▪

Possible unit of pulse

0.1 pulse/kwh 1 pulse/kwh 10 pulse/kwh
100 pulse/kwh 1000 pulse/kwh

Those values can be set by the main controller. (Refer to the menu tree in "9-3. Main Settings Menu".)

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34

<Running information>

This function shows current temperature and other data of main component parts

of both the indoor and outdoor units.

1. From the Service menu highlight Running information.

2. Press CONFIRM.

3. Press F3 and F4 buttons to set the Ref. address. *1

4. Use the function buttons to enter index code for the component to be viewed.
(See the Table 9-4-1 for component index codes.)

5. Press CONFIRM.

*1 For multiple outdoor units control system only.

<Thermistor reading>

This function shows the current readings of thermistors located on the water and refrigerant circuit

Thermistor Description Thermistor Description

TH1A Zone 1 room temperature THW6 Zone 1 flow water temperature
TH1B Zone 2 room temperature THW7 Zone 1 return water temperature
TH2 Refrigerant return temperature THW8 Zone 2 flow water temperature
THW1 Water flow temperature THW9 Zone 2 return water temperature
THW2 Water return temperature THWB1 Boiler flow water temperature
THW5 DHW tank water temperature THWB2 Boiler return water temperature
TH7 Ambient (outdoor) temperature

External input settings menu screen

Demand control screen

Outdoor thermostat setting screen

<External input settings>

Demand control(IN4)

Outdoor thermostat (IN5)

The selection of “OFF”, whilst a signal is being sent to IN4, forcefully stops all

the heat source operations and the selection of “Boiler” stops operations of
heat pump and electric heater and performs boiler operation.

The selection of “Heater”, whilst a signal is being sent to IN5, performs

electric-heater-only operation and the selection of “Boiler” performs boiler
operation.

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35

<Summary of settings>

This function shows the current installer/user entered settings.

Abbreviation

Explanation

Abbreviation

Explanation

HWtemp DHW max temperature Z2 mode Operation mode
HWdrop DHW temperature drop - HER (Heating room temperature)
HWtime DHW max operation time - HE (Heating flow temperature)
NO HW DHW mode restriction - HCC (Heating compensation curve)
HWset DHW operation mode (Normal/Eco) - COR (—)

- CO (Cooling flow temperature)

Ltemp Legionella hot water temperature Hroom 1 Heating target room temperature
Lfreq Legionella operation Frequency Hroom 2 Heating target room temperature
Lstart Legionella mode start time Hflow 1 Heating target flow temperature
Ltime Legionella max. operation time Hflow 2 Heating target flow temperature
Lkeep Duration of max (Legionella) hot

water temperature

Croom 1 Cooling target room temperature
Croom 2 Cooling target room temperature

Z1 mode Operation mode Cflow 1 Cooling target flow temperature

- HER (Heating room temperature) Cflow 2 Cooling target flow temperature

- HE (Heating flow temperature) FSflow Freeze stat function flow temperature

- HCC (Heating compensation curve) FSout

Freeze stat function ambient temperature

- COR (—)

- CO (Cooling flow temperature)

<Error history>

Error history allows the service engineer to view previous Error codes, the unit
address and the date on which they occurred. Up to 16 Error codes can be stored

in the history the most recent Error event is displayed at the top of the list.

1. From the service menu select Error history

2. Press CONFIRM.

Please see chapter 10-4. for error code diagnosis and actions.

To delete an Error history item;

1. From Error history screen press F4 button (Rubbish bin icon)

2. Then press F3 button (Yes).

Password input screen

Password verify screen

<Password protection>

Password protection is available to prevent unauthorised access to the service

menu by untrained persons.

1. From the service menu use F1 and F2 buttons to scroll through list until
Password protection is highlighted.

2. Press CONFIRM.

3. When password input screen is displayed use buttons F1 and F2 to move left
and right between the four digits, F3 to lower the selected digit by 1, and F4 to
increase the selected digit by 1.

4. When you have input your password press CONFIRM.

5. The password verify screen is displayed.

6. To verify your new password press button F3.

7. Your password is now set and the completion screen is displayed.

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36

<SD card>

The use of an SD memory card simplies the main controller settings in the eld.
*Ecodan service tool (for use with PC tool) is necessary for the setting.

SD Main RC

1. From the SD card setting use F1 and F2 buttons to scroll through list until
“SD

Main RC” is highlighted.

2. Press CONFIRM.

3. Press F3 and F4 buttons to set the Ref. address. *1

4. Use F1, F2 and F3 buttons to select a menu to write to the main controller.

5. Press CONFIRM to start downloading.

6. Wait for a few minutes until “Complete!” appears.

*1 For multiple outdoor units control system only.

Main RC SD

1. From the SD card setting use F1 and F2 buttons to scroll through list until
Main RC

SD is highlighted.

2. Press CONFIRM.

3. Press F3 and F4 buttons to set the Ref. address. *1

4. Use F1, F2 and F3 buttons to select a menu to write to the SD memory card.

5. Press CONFIRM to start uploading.

6. Wait for a few minutes until “Complete!” appears.

*1 For multiple outdoor units control system only.

Completion screen

Resetting the password

If you forget the password you entered, or have to service a unit somebody else
installed, you can reset the password to the factory default of 0000.

1. From the main settings menu scroll down the functions until Service Menu is
highlighted.

2. Press CONFIRM.

3. You will be prompted to enter a password.

4. Hold down buttons F3 and F4 together for 3 secs

5. You will be asked if you wish to continue and reset the password to default set­ting.

6. To reset press button F3.

7. The password is now reset to 0000.

<Manual reset>

Should you wish to restore the factory settings at any time you should use the
manual reset function. Please note this will reset ALL functions to the factory de­fault settings.

1. From the service menu use F1 and F2 buttons to scroll through list until Manual
Reset is highlighted.

2. Press CONFIRM.

3. The Manual reset screen is displayed.

4. Choose either Manual Reset for FTC or Main Controller.

5. Press F3 button to conrm manual reset of chosen device.

OCH570

37

Note
Refer to outdoor unit service manual for request code 0 to 102, 106 to 149.
Request codes 103 to 105 indicate error histories of both indoor and outdoor units.
As only four digits can be displayed at one time the software version number is displayed in two halves.

Entercode190toseetherstfourdigitsandcode191toseethelastfourdigits.

For example software version No. 5.01 A000, when code 190 is entered 0501 is displayed, when code 191 is entered A000 is displayed.

<Table 9-4-1>

Request

code

Request content Range Unit

103 Error history 1 (latest) Displays error history. ("– –" is displays if no history is present.) Code
104 Error history 2 (second to last) Displays error history. ("– –" is displays if no history is present.) —
105 Error history 3 (third to last) Displays error history. ("– –" is displays if no history is present.) —
154 Water circulation pump 1 - Accumulated operating time (after reset) 0 - 9999 10 hours
156 Water circulation pump 2 - Accumulated operating time (after reset) 0 - 9999 10 hours
157 Water circulation pump 3 - Accumulated operating time (after reset) 0 - 9999 10 hours
158 Water circulation pump 4 - Accumulated operating time (after reset) 0 - 9999 10 hours
162 Indoor unit - DIP SW1 setting information Refer to detail contents described hereinafter. —
163 Indoor unit - DIP SW2 setting information Refer to detail contents described hereinafter. —
164 Indoor unit - DIP SW3 setting information Refer to detail contents described hereinafter. —
165 Indoor unit - DIP SW4 setting information Refer to detail contents described hereinafter. —
166 Indoor unit - DIP SW5 setting information Refer to detail contents described hereinafter. —
175 Indoor unit - Output signal information Refer to detail contents described hereinafter. —
176 Indoor unit - Input signal information Refer to detail contents described hereinafter. —
177 Mixing valve opening step 0 - 10 Step
190 Indoor unit - Software version 1st 4 digits Refer to Note below. —
191 Indoor unit - Software version last 4 digits Refer to Note below. —
340 Water circulation pump 1 - Accumulated operating time reset — —
342 Water circulation pump 2 - Accumulated operating time reset — —
343 Water circulation pump 3 - Accumulated operating time reset — —
344 Water circulation pump 4 - Accumulated operating time reset — —
504 Indoor unit - Zone 1 room temp. (TH1A) –39 - 88 °C
505 Indoor unit - Ref. liquid temp. (TH2) –39 - 88 °C
506 Indoor unit - Return water temp. (THW2) –39 - 88 °C
507 Indoor unit - Zone 2 room temp. (TH1B) –39 - 88 °C
508 Indoor unit - DHW tank water temp. (THW5) –39 - 88 °C
509 Indoor unit - Zone 1 ow water temp. (THW6) –39 - 88 °C
510 Indoor unit - Outside air temp. (TH7) –39 - 88 °C

511 Indoor unit - Flow water temp. (THW1) –39 - 88 °C
512 Indoor unit - Zone 1 return water temp. (THW7) –39 - 88 °C
513 Indoor unit - Zone 2 flow water temp. (THW8) –39 - 88 °C
514 Indoor unit - Zone 2 return water temp. (THW9) –39 - 88 °C
515 Indoor unit - Boiler flow water temp. (THWB1) –40 - 140 °C
516 Indoor unit - Boiler return water temp. (THWB2) –40 - 140 °C
540 Flow rate of the primary circuit 0 - 100 L/min.

550 Indoor unit - Error postponement history 1 (latest)

Displays postponement code.

("– –" is displays if no postponement code is present.)

—

551 Indoor unit - Operation control at time of error 0 Standard, 1 Heater, 2 Boiler —

552

Indoor unit - Operation mode at time of error 0 OFF, 1 DHW, 2 Heating, 3 Cooling, 4 Legionella prevention,

5 Freeze protection, 6 Operation stop, 7 Defrost

—

553 Indoor unit - Output signal information at time of error Refer to detail contents described hereinafter —
554 Indoor unit - Input signal information at time of error Refer to detail contents described hereinafter —
555 Indoor unit - Zone 1 room temp. (TH1A) at time of error –39 - 88 °C
556 Indoor unit - Zone 2 room temp. (TH1B) at time of error –39 - 88 °C
557 Indoor unit - Ref. liquid temp. (TH2) at time of error –39 - 88 °C
558 Indoor unit - Flow water temp. (THW1) at time of error –39 - 88 °C
559 Indoor unit - Return water temp. (THW2) at time of error –39 - 88 °C
560 Indoor unit - DHW tank water temp. (THW5) at time of error –39 - 88 °C
561 Indoor unit - Zone 1 flow water temp. (THW6) at time of error –39 - 88 °C
562 Indoor unit - Zone 1 return water temp. (THW7) at time of error –39 - 88 °C
563 Indoor unit - Zone 2 flow water temp. (THW8) at time of error –39 - 88 °C
564 Indoor unit - Zone 2 return water temp. (THW9) at time of error –39 - 88 °C
565 Indoor unit - Boiler flow water temp. (THWB1) at time of error –40 - 140 °C
566 Indoor unit - Boiler return water temp. (THWB2) at time of error –40 - 140 °C

567

Indoor unit - Failure (P1/P2/L5/L8/Ld) thermistor 0 Failure thermistor is none, 1 TH1A, 2 TH2, 3 THW1, 4 THW2,

5 THWB1, 6 THW5, 7 THWB2, 8 TH1B, A THW6, B THW7,
C THW8, D THW9

—

568 Mixing valve opening step at time of error 0 - 10 Step

569

Operated Flow switch at time of failure (L9) 0 No operated flow switch, 1 Flow switch 1, 2 Flow switch 2,

3 Flow switch 3

—

571 Flow rate at time of error 0 - 100 L/min.

OCH570

38

Indoor unit switch setting display (Request code: 162 to 166)

0: OFF 1: ON

SW1, SW2, SW3, SW4, SW5

Display

1 2 3 4 5 6 7 8
0 0 0 0 0 0 0 0 00 00
1 0 0 0 0 0 0 0 00 01
0 1 0 0 0 0 0 0 00 02
1 1 0 0 0 0 0 0 00 03
0 0 1 0 0 0 0 0 00 04
1 0 1 0 0 0 0 0 00 05
0 1 1 0 0 0 0 0 00 06
1 1 1 0 0 0 0 0 00 07
0 0 0 1 0 0 0 0 00 08
1 0 0 1 0 0 0 0 00 09
0 1 0 1 0 0 0 0 00 0A
1 1 0 1 0 0 0 0 00 0B
0 0 1 1 0 0 0 0 00 0C
1 0 1 1 0 0 0 0 00 0D
0 1 1 1 0 0 0 0 00 0E
1 1 1 1 0 0 0 0 00 0F
0 0 0 0 1 0 0 0 00 10

1 0 0 0 1 0 0 0 00 11
0 1 0 0 1 0 0 0 00 12
1 1 0 0 1 0 0 0 00 13
0 0 1 0 1 0 0 0 00 14
1 0 1 0 1 0 0 0 00 15
0 1 1 0 1 0 0 0 00 16
1 1 1 0 1 0 0 0 00 17
0 0 0 1 1 0 0 0 00 18
1 0 0 1 1 0 0 0 00 19
0 1 0 1 1 0 0 0 00 1A
1 1 0 1 1 0 0 0 00 1B
0 0 1 1 1 0 0 0 00 1C
1 0 1 1 1 0 0 0 00 1D
0 1 1 1 1 0 0 0 00 1E
1 1 1 1 1 0 0 0 00 1F
0 0 0 0 0 1 0 0 00 20
1 0 0 0 0 1 0 0 00 21
0 1 0 0 0 1 0 0 00 22
1 1 0 0 0 1 0 0 00 23
0 0 1 0 0 1 0 0 00 24
1 0 1 0 0 1 0 0 00 25
0 1 1 0 0 1 0 0 00 26
1 1 1 0 0 1 0 0 00 27
0 0 0 1 0 1 0 0 00 28
1 0 0 1 0 1 0 0 00 29
0 1 0 1 0 1 0 0 00 2A
1 1 0

1 0 1 0 0 00 2B
0 0 1 1 0 1 0 0 00 2C
1 0 1 1 0 1 0 0 00 2D
0 1 1 1 0 1 0 0 00 2E
1 1 1 1 0 1 0 0 00 2F
0 0 0 0 1 1 0 0 00 30
1 0 0 0 1 1 0 0 00 31
0 1 0 0 1 1 0 0 00 32
1 1 0 0 1 1 0 0 00 33
0 0 1 0 1 1 0 0 00 34
1 0 1 0 1 1 0 0 00 35
0 1 1 0 1 1 0 0 00 36
1 1 1 0 1 1 0 0 00 37
0 0 0 1 1 1 0 0 00 38
1 0 0 1 1 1 0 0 00 39
0 1 0 1 1 1 0 0 00 3A
1 1 0 1 1 1 0 0 00 3B
0 0 1 1 1 1 0 0 00 3C

1 0 1 1 1 1 0 0 00 3D
0 1 1 1 1 1 0 0 00 3E
1 1 1 1 1 1 0 0 00 3F

0: OFF

1: ON

SW1, SW2, SW3, SW4, SW5

Display

1 2 3 4 5 6 7 8
0 0 0 0 0 0 1 0 00 40
1 0 0 0 0 0 1 0 00 41
0 1 0 0 0 0 1 0 00 42
1 1 0 0 0 0 1 0 00 43
0 0 1 0 0 0 1 0 00 44
1 0 1 0 0 0 1 0 00 45
0 1 1 0 0 0 1 0 00 46
1 1 1 0 0 0 1 0 00 47
0 0 0 1 0 0 1 0 00 48
1 0 0 1 0 0 1 0 00 49
0 1 0 1 0 0 1 0 00 4A
1 1 0 1 0 0 1 0 00 4B
0 0 1 1 0 0 1 0 00 4C
1 0 1 1 0 0 1 0 00 4D
0 1 1 1 0 0 1 0 00 4E
1 1 1 1 0 0 1 0 00 4F
0 0 0 0 1 0 1 0 00 50
1 0 0 0 1 0 1 0 00 51
0 1 0 0 1 0 1 0 00 52
1 1 0 0 1 0 1 0 00 53
0 0 1 0 1 0 1 0 00 54
1 0 1 0 1 0 1 0 00 55
0 1 1 0 1 0 1 0 00 56
1 1 1 0 1 0 1 0 00 57
0 0 0 1 1 0 1 0 00 58
1 0 0 1 1 0 1 0 00 59
0 1 0 1 1 0 1 0 00 5A
1 1 0 1 1 0 1 0 00 5B
0 0 1 1 1 0 1 0 00 5C
1 0 1 1 1 0 1 0 00 5D
0 1 1 1 1 0 1 0 00 5E
1 1 1 1 1 0 1 0 00 5F
0 0 0 0 0 1 1 0 00 60
1 0 0 0 0 1 1 0 00 61
0 1 0 0 0 1 1 0 00 62
1 1 0 0 0 1 1 0 00 63
0 0 1 0 0 1 1 0 00 64
1 0 1 0 0 1 1 0 00 65
0 1 1 0 0 1 1 0 00 66
1 1 1 0 0 1 1 0 00 67
0 0 0 1 0 1 1 0 00 68

1 0 0 1 0 1 1 0 00 69
0 1 0 1 0 1 1 0 00 6A
1 1 0

1 0 1 1 0 00 6B
0 0 1 1 0 1 1 0 00 6C
1 0 1 1 0 1 1 0 00 6D
0 1 1 1 0 1 1 0 00 6E
1 1 1 1 0 1 1 0 00 6F
0 0 0 0 1 1 1 0 00 70
1 0 0 0 1 1 1 0 00 71
0 1 0 0 1 1 1 0 00 72
1 1 0 0 1 1 1 0 00 73
0 0 1 0 1 1 1 0 00 74
1 0 1 0 1 1 1 0 00 75
0 1 1 0 1 1 1 0 00 76
1 1 1 0 1 1 1 0 00 77
0 0 0 1 1 1 1 0 00 78
1 0 0 1 1 1 1 0 00 79
0 1 0 1 1 1 1 0 00 7A
1 1 0 1 1 1 1 0 00 7B
0 0 1 1 1 1 1 0 00 7C
1 0 1 1 1 1 1 0 00 7D
0 1 1 1 1 1 1 0 00 7E
1 1 1 1 1 1 1 0 00 7F

OCH570

39

Indoor unit switch setting display (Request code: 162 to 166)

0: OFF 1: ON

SW1, SW2, SW3, SW4, SW5

Display

1 2 3 4 5 6 7 8
0 0 0 0 0 0 0 1 00 80
1 0 0 0 0 0 0 1 00 81
0 1 0 0 0 0 0 1 00 82
1 1 0 0 0 0 0 1 00 83
0 0 1 0 0 0 0 1 00 84
1 0 1 0 0 0 0 1 00 85
0 1 1 0 0 0 0 1 00 86
1 1 1 0 0 0 0 1 00 87
0 0 0 1 0 0 0 1 00 88
1 0 0 1 0 0 0 1 00 89
0 1 0 1 0 0 0 1 00 8A
1 1 0 1 0 0 0 1 00 8B
0 0 1 1 0 0 0 1 00 8C
1 0 1 1 0 0 0 1 00 8D
0 1 1 1 0 0 0 1 00 8E
1 1 1 1 0 0 0 1 00 8F

0 0 0 0 1 0 0 1 00 90
1 0 0 0 1 0 0 1 00 91
0 1 0 0 1 0 0 1 00 92
1 1 0 0 1 0 0 1 00 93
0 0 1 0 1 0 0 1 00 94
1 0 1 0 1 0 0 1 00 95
0 1 1 0 1 0 0 1 00 96
1 1 1 0 1 0 0 1 00 97
0 0 0 1 1 0 0 1 00 98
1 0 0 1 1 0 0 1 00 99
0 1 0 1 1 0 0 1 00 9A
1 1 0 1 1 0 0 1 00 9B
0 0 1 1 1 0 0 1 00 9C
1 0 1 1 1 0 0 1 00 9D
0 1 1 1 1 0 0 1 00 9E
1 1 1 1 1 0 0 1 00 9F
0 0 0 0 0 1 0 1 00 A0
1 0 0 0 0 1 0 1 00 A1
0 1 0 0 0 1 0 1 00 A2
1 1 0 0 0 1 0 1 00 A3
0 0 1 0 0 1 0 1 00 A4
1 0 1 0 0 1 0 1 00 A5
0 1 1 0 0 1 0 1 00 A6
1 1 1 0 0 1 0 1 00 A7
0 0 0 1 0 1 0 1 00 A8
1 0 0 1 0 1 0 1 00 A9
0 1 0 1 0 1 0 1 00 AA
1 1 0

1 0 1 0 1 00 AB
0 0 1 1 0 1 0 1 00 AC
1 0 1 1 0 1 0 1 00 AD
0 1 1 1 0 1 0 1 00 AE
1 1 1 1 0 1 0 1 00 AF
0 0 0 0 1 1 0 1 00 B0
1 0 0 0 1 1 0 1 00 B1
0 1 0 0 1 1 0 1 00 B2
1 1 0 0 1 1 0 1 00 B3
0 0 1 0 1 1 0 1 00 B4
1 0 1 0 1 1 0 1 00 B5
0 1 1 0 1 1 0 1 00 B6
1 1 1 0 1 1 0 1 00 B7
0 0 0 1 1 1 0 1 00 B8
1 0 0 1 1 1 0 1 00 B9
0 1 0 1 1 1 0 1 00 BA
1 1 0 1 1 1 0 1 00 BB
0 0 1 1 1 1 0 1 00 BC
1 0 1 1 1 1 0 1 00 BD
0 1 1 1 1 1 0 1 00 BE

1 1 1 1 1 1 0 1 00 BF

0: OFF

1: ON

SW1, SW2, SW3, SW4, SW5

Display

1 2 3 4 5 6 7 8
0 0 0 0 0 0 1 1 00 C0
1 0 0 0 0 0 1 1 00 C1
0 1 0 0 0 0 1 1 00 C2
1 1 0 0 0 0 1 1 00 C3
0 0 1 0 0 0 1 1 00 C4
1 0 1 0 0 0 1 1 00 C5
0 1 1 0 0 0 1 1 00 C6
1 1 1 0 0 0 1 1 00 C7
0 0 0 1 0 0 1 1 00 C8
1 0 0 1 0 0 1 1 00 C9
0 1 0 1 0 0 1 1 00 CA
1 1 0 1 0 0 1 1 00 CB
0 0 1 1 0 0 1 1 00 CC
1 0 1 1 0 0 1 1 00 CD
0 1 1 1 0 0 1 1 00 CE
1 1 1 1 0 0 1 1 00 CF
0 0 0 0 1 0 1 1 00 D0
1 0 0 0 1 0 1 1 00 D1
0 1 0 0 1 0 1 1 00 D2
1 1 0 0 1 0 1 1 00 D3
0 0 1 0 1 0 1 1 00 D4
1 0 1 0 1 0 1 1 00 D5
0 1 1 0 1 0 1 1 00 D6
1 1 1 0 1 0 1 1 00 D7

0 0 0 1 1 0 1 1 00 D8
1 0 0 1 1 0 1 1 00 D9
0 1 0 1 1 0 1 1 00 DA
1 1 0 1 1 0 1 1 00 DB
0 0 1 1 1 0 1 1 00 DC
1 0 1 1 1 0 1 1 00 DD
0 1 1 1 1 0 1 1 00 DE
1 1 1 1 1 0 1 1 00 DF
0 0 0 0 0 1 1 1 00 E0
1 0 0 0 0 1 1 1 00 E1
0 1 0 0 0 1 1 1 00 E2
1 1 0 0 0 1 1 1 00 E3
0 0 1 0 0 1 1 1 00 E4
1 0 1 0 0 1 1 1 00 E5
0 1 1 0 0 1 1 1 00 E6
1 1 1 0 0 1 1 1 00 E7
0 0 0 1 0 1 1 1 00 E8
1 0 0 1 0 1 1 1 00 E9
0 1 0 1 0 1 1 1 00 EA
1 1 0

1 0 1 1 1 00 EB
0 0 1 1 0 1 1 1 00 EC
1 0 1 1 0 1 1 1 00 ED
0 1 1 1 0 1 1 1 00 EE
1 1 1 1 0 1 1 1 00 EF
0 0 0 0 1 1 1 1 00 F0
1 0 0 0 1 1 1 1 00 F1
0 1 0 0 1 1 1 1 00 F2
1 1 0 0 1 1 1 1 00 F3
0 0 1 0 1 1 1 1 00 F4
1 0 1 0 1 1 1 1 00 F5
0 1 1 0 1 1 1 1 00 F6
1 1 1 0 1 1 1 1 00 F7
0 0 0 1 1 1 1 1 00 F8
1 0 0 1 1 1 1 1 00 F9
0 1 0 1 1 1 1 1 00 F

A
1 1 0 1 1 1 1 1 00 FB
0 0 1 1 1 1 1 1 00 FC
1 0 1 1 1 1 1 1 00 FD
0 1 1 1 1 1 1 1 00 FE
1 1 1 1 1 1 1 1 00 FF

OCH570

40

Output signal display (Request code: 175/553)

Please refer to Table 2 on relevant wiring diagram whilst using the following.

0: OFF 1: ON

OUT

Display

1 2 3 4 5A 5B 6 7
0 0 0 0 0 0 0 0 xx 00
1 0 0 0 0 0 0 0 xx 01
0 1 0 0 0 0 0 0 xx 02
1 1 0 0 0 0 0 0 xx 03
0 0 1 0 0 0 0 0 xx 04
1 0 1 0 0 0 0 0 xx 05
0 1 1 0 0 0 0 0 xx 06
1 1 1 0 0 0 0 0 xx 07
0 0 0 1 0 0 0 0 xx 08
1 0 0 1 0 0 0 0 xx 09
0 1 0 1 0 0 0 0 xx 0A
1 1 0 1 0 0 0 0 xx 0B
0 0 1 1 0 0 0 0 xx 0C
1 0 1 1 0 0 0 0 xx 0D
0 1 1 1 0 0 0 0 xx 0E
1 1 1 1 0 0 0 0 xx 0F
0 0 0 0 1 0 0 0 xx 10
1 0 0 0 1 0 0 0 xx 11
0 1 0 0 1 0 0 0 xx 12
1 1 0 0 1 0 0 0 xx 13
0 0 1 0 1 0 0 0 xx 14
1 0 1 0 1 0 0 0 xx 15
0 1 1 0 1 0 0 0 xx 16
1 1 1 0 1 0 0 0 xx 17
0 0 0 1 1 0 0 0 xx 18
1 0 0 1 1 0 0 0 xx 19
0 1 0 1 1 0 0 0 xx 1A
1 1 0 1 1 0 0 0 xx 1B
0 0 1 1 1 0 0 0 xx 1C
1 0 1 1 1 0 0 0 xx 1D

0 1 1 1 1 0 0 0 xx 1E
1 1 1 1 1 0 0 0 xx 1F
0 0 0 0 0 1 0 0 xx 20
1 0 0 0 0 1 0 0 xx 21
0 1 0 0 0 1 0 0 xx 22
1 1 0 0 0 1 0 0 xx 23
0 0 1 0 0 1 0 0 xx 24
1 0 1 0 0 1 0 0 xx 25
0 1 1 0 0 1 0 0 xx 26
1 1 1 0 0 1 0 0 xx 27
0 0 0 1 0 1 0 0 xx 28
1 0 0 1 0 1 0 0 xx 29
0 1 0 1 0 1 0 0 xx 2A
1 1 0

1 0 1 0 0 xx

2B

0 0 1 1 0 1 0 0 xx 2C
1 0 1 1 0 1 0 0 xx 2D
0 1 1 1 0 1 0 0 xx 2E
1 1 1 1 0 1 0 0 xx 2F
0 0 0 0 1 1 0 0 xx 30
1 0 0 0 1 1 0 0 xx 31
0 1 0 0 1 1 0 0 xx 32
1 1 0 0 1 1 0 0 xx 33
0 0 1 0 1 1 0 0 xx 34
1 0 1 0 1 1 0 0 xx 35
0 1 1 0 1 1 0 0 xx 36
1 1 1 0 1 1 0 0 xx 37
0 0 0 1 1 1 0 0 xx 38
1 0 0 1 1 1 0 0 xx 39
0 1 0 1 1 1 0 0 xx 3A
1 1 0 1 1 1 0 0 xx 3B
0 0 1 1 1 1 0 0 xx 3C
1 0 1 1 1 1 0 0 xx 3D
0 1 1 1 1 1 0 0 xx 3E
1 1 1 1 1 1 0 0 xx 3F

0: OFF 1: ON

OUT

Display

1 2 3 4 5A 5B 6 7
0 0 0 0 0 0 1 0 xx 40
1 0 0 0 0 0 1 0 xx 41
0 1 0 0 0 0 1 0 xx 42
1 1 0 0 0 0 1 0 xx 43
0 0 1 0 0 0 1 0 xx 44
1 0 1 0 0 0 1 0 xx 45
0 1 1 0 0 0 1 0 xx 46
1 1 1 0 0 0 1 0 xx 47
0 0 0 1 0 0 1 0 xx 48
1 0 0 1 0 0 1 0 xx 49
0 1 0 1 0 0 1 0 xx 4A
1 1 0 1 0 0 1 0 xx 4B
0 0 1 1 0 0 1 0 xx 4C
1 0 1 1 0 0 1 0 xx 4D
0 1 1 1 0 0 1 0 xx 4E
1 1 1 1 0 0 1 0 xx 4F
0 0 0 0 1 0 1 0 xx 50
1 0 0 0 1 0 1 0 xx 51
0 1 0 0 1 0 1 0 xx 52
1 1 0 0 1 0 1 0 xx 53
0 0 1 0 1 0 1 0 xx 54
1 0 1 0 1 0 1 0 xx 55
0 1 1 0 1 0 1 0 xx 56
1 1 1 0 1 0 1 0 xx 57
0 0 0 1 1 0 1 0 xx 58
1 0 0 1 1 0 1 0 xx 59
0 1 0 1 1 0 1 0 xx 5A
1 1 0 1 1 0 1 0 xx 5B
0 0 1 1 1 0 1 0 xx 5C
1 0 1 1 1 0 1 0 xx 5D
0 1 1 1 1 0 1 0 xx 5E
1 1 1 1 1 0 1 0 xx 5F
0 0 0 0 0 1 1 0 xx 60
1 0 0 0 0 1 1 0 xx 61
0 1 0 0 0 1 1 0 xx 62
1 1 0 0 0 1 1 0 xx 63
0 0 1 0 0 1 1 0 xx 64
1 0 1 0 0 1 1 0 xx 65
0 1 1 0 0 1 1 0 xx 66
1 1 1 0 0 1 1 0 xx 67
0 0 0 1 0 1 1 0 xx 68
1 0 0 1 0 1 1 0 xx 69
0 1 0 1 0 1 1 0 xx 6A
1 1 0

1 0 1 1 0 xx

6B

0 0 1 1 0 1 1 0 xx 6C
1 0 1 1 0 1 1 0 xx 6D
0 1 1 1 0 1 1 0 xx 6E
1 1 1 1 0 1 1 0 xx 6F
0 0 0 0 1 1 1 0 xx 70
1 0 0 0 1 1 1 0 xx 71
0 1 0 0 1 1 1 0 xx 72
1 1 0 0 1 1 1 0 xx 73
0 0 1 0 1 1 1 0 xx 74
1 0 1 0 1 1 1 0 xx 75
0 1 1 0 1 1 1 0 xx 76
1 1 1 0 1 1 1 0 xx 77
0 0 0 1 1 1 1 0 xx 78
1 0 0 1 1 1 1 0 xx 79
0 1 0 1 1 1 1 0 xx 7A
1 1 0 1 1 1 1 0 xx 7B
0 0 1 1 1 1 1 0 xx 7C
1 0 1 1 1 1 1 0 xx 7D
0 1 1 1 1 1 1 0 xx 7E
1 1 1 1 1 1 1 0 xx 7F

OCH570

41

Output signal display (Request code: 175/553)

Please refer to Table 2 on relevant wiring diagram whilst using the following.

0: OFF 1: ON

OUT

Display

1 2 3 4 5A 5B 6 7
0 0 0 0 0 0 0 1 xx 80
1 0 0 0 0 0 0 1 xx 81
0 1 0 0 0 0 0 1 xx 82
1 1 0 0 0 0 0 1 xx 83
0 0 1 0 0 0 0 1 xx 84
1 0 1 0 0 0 0 1 xx 85
0 1 1 0 0 0 0 1 xx 86
1 1 1 0 0 0 0 1 xx 87
0 0 0 1 0 0 0 1 xx 88
1 0 0 1 0 0 0 1 xx 89
0 1 0 1 0 0 0 1 xx 8A
1 1 0 1 0 0 0 1 xx 8B
0 0 1 1 0 0 0 1 xx 8C
1 0 1 1 0 0 0 1 xx 8D
0 1 1 1 0 0 0 1 xx 8E
1 1 1 1 0 0 0 1 xx 8F
0 0 0 0 1 0 0 1 xx 90
1 0 0 0 1 0 0 1 xx 91
0 1 0 0 1 0 0 1 xx 92
1 1 0 0 1 0 0 1 xx 93
0 0 1 0 1 0 0 1 xx 94
1 0 1 0 1 0 0 1 xx 95
0 1 1 0 1 0 0 1 xx 96
1 1 1 0 1 0 0 1 xx 97
0 0 0 1 1 0 0 1 xx 98
1 0 0 1 1 0 0 1 xx 99
0 1 0 1 1 0 0 1 xx 9A
1 1 0 1 1 0 0 1 xx 9B
0 0 1 1 1 0 0 1 xx 9C
1 0 1 1 1 0 0 1 xx 9D
0 1 1 1 1 0 0 1 xx 9E
1 1 1 1 1 0 0 1 xx 9F
0 0 0 0 0 1 0 1 xx A0
1 0 0 0 0 1 0 1 xx A1
0 1 0 0 0 1 0 1 xx A2
1 1 0 0 0 1 0 1 xx A3
0 0 1 0 0 1 0 1 xx A4
1 0 1 0 0 1 0 1 xx A5
0 1 1 0 0 1 0 1 xx A6
1 1 1 0 0 1 0 1 xx A7
0 0 0 1 0 1 0 1 xx A8
1 0 0 1 0 1 0 1 xx A9
0 1 0 1 0 1 0 1 xx AA
1 1 0

1 0 1 0 1 xx

AB

0 0 1 1 0 1 0 1 xx AC
1 0 1 1 0 1 0 1 xx AD
0 1 1 1 0 1 0 1 xx AE
1 1 1 1 0 1 0 1 xx AF
0 0 0 0 1 1 0 1 xx B0
1 0 0 0 1 1 0 1 xx B1
0 1 0 0 1 1 0 1 xx B2
1 1 0 0 1 1 0 1 xx B3
0 0 1 0 1 1 0 1 xx B4
1 0 1 0 1 1 0 1 xx B5
0 1 1 0 1 1 0 1 xx B6
1 1 1 0 1 1 0 1 xx B7
0 0 0 1 1 1 0 1 xx B8
1 0 0 1 1 1 0 1 xx B9
0 1 0 1 1 1 0 1 xx BA
1 1 0 1 1 1 0 1 xx BB
0 0 1 1 1 1 0 1 xx BC
1 0 1 1 1 1 0 1 xx BD
0 1 1 1 1 1 0 1 xx BE
1 1 1 1 1 1 0 1 xx BF

0: OFF 1: ON

OUT

Display

1 2 3 4 5A 5B 6 7
0 0 0 0 0 0 1 1 xx C0
1 0 0 0 0 0 1 1 xx C1
0 1 0 0 0 0 1 1 xx C2
1 1 0 0 0 0 1 1 xx C3
0 0 1 0 0 0 1 1 xx C4
1 0 1 0 0 0 1 1 xx C5
0 1 1 0 0 0 1 1 xx C6
1 1 1 0 0 0 1 1 xx C7
0 0 0 1 0 0 1 1 xx C8
1 0 0 1 0 0 1 1 xx C9
0 1 0 1 0 0 1 1 xx CA
1 1 0 1 0 0 1 1 xx CB
0 0 1 1 0 0 1 1 xx CC
1 0 1 1 0 0 1 1 xx CD
0 1 1 1 0 0 1 1 xx CE
1 1 1 1 0 0 1 1 xx CF
0 0 0 0 1 0 1 1 xx D0
1 0 0 0 1 0 1 1 xx D1
0 1 0 0 1 0 1 1 xx D2
1 1 0 0 1 0 1 1 xx D3
0 0 1 0 1 0 1 1 xx D4
1 0 1 0 1 0 1 1 xx D5
0 1 1 0 1 0 1 1 xx D6
1 1 1 0 1 0 1 1 xx D7
0 0 0 1 1 0 1 1 xx D8
1 0 0 1 1 0 1 1 xx D9
0 1 0 1 1 0 1 1 xx DA
1 1 0 1 1 0 1 1 xx DB
0 0 1 1 1 0 1 1 xx DC
1 0 1 1 1 0 1 1 xx DD
0 1 1 1 1 0 1 1 xx DE
1 1 1 1 1 0 1 1 xx DF
0 0 0 0 0 1 1 1 xx E0
1 0 0 0 0 1 1 1 xx E1
0 1 0 0 0 1 1 1 xx E2
1 1 0 0 0 1 1 1 xx E3
0 0 1 0 0 1 1 1 xx E4
1 0 1 0 0 1 1 1 xx E5
0 1 1 0 0 1 1 1 xx E6
1 1 1 0 0 1 1 1 xx E7
0 0 0 1 0 1 1 1 xx E8
1 0 0 1 0 1 1 1 xx E9
0 1 0 1 0 1 1 1 xx EA
1 1 0

1 0 1 1 1 x

x EB

0 0 1 1 0 1 1 1 xx EC
1 0 1 1 0 1 1 1 xx ED
0 1 1 1 0 1 1 1 xx EE
1 1 1 1 0 1 1 1 xx EF
0 0 0 0 1 1 1 1 xx F0
1 0 0 0 1 1 1 1 xx F1
0 1 0 0 1 1 1 1 xx F2
1 1 0 0 1 1 1 1 xx F3
0 0 1 0 1 1 1 1 xx F4
1 0 1 0 1 1 1 1 xx F5
0 1 1 0 1 1 1 1 xx F6
1 1 1 0 1 1 1 1 xx F7
0 0 0 1 1 1 1 1 xx F8
1 0 0 1 1 1 1 1 xx F9
0 1 0 1 1 1 1 1 xx FA
1 1 0 1 1 1 1 1 xx FB
0 0 1 1 1 1 1 1 xx FC
1 0 1 1 1 1 1 1 xx FD
0 1 1 1 1 1 1 1 xx FE
1 1 1 1 1 1 1 1 xx FF

OCH570

42

Output signal display (Request code: 175/553)

Please refer to Table 2 on relevant wiring diagram whilst using the following.

Mixing valve state

OUT

Mixing valve state

5A 5B

0 0 Stop
0 1 Stop
1 0 Open
1 1 Close

0: OFF 1: ON

OUT

Display

8 * 9 10 11 12 13 14 15

0 0 0 0 0 0 0 0 00 xx
1 0 0 0 0 0 0 0 01 xx
0 1 0 0 0 0 0 0 02 xx
1 1 0 0 0 0 0 0 03 xx
0 0 1 0 0 0 0 0 04 xx
1 0 1 0 0 0 0 0 05 xx
0 1 1 0 0 0 0 0 06 xx
1 1 1 0 0 0 0 0 07 xx
0 0 0 1 0 0 0 0 08 xx
1 0 0 1 0 0 0 0 09 xx
0 1 0 1 0 0 0 0 0A xx
1 1 0 1 0 0 0 0 0B xx
0 0 1 1 0 0 0 0 0C xx
1 0 1 1 0 0 0 0 0D xx
0 1 1 1 0 0 0 0 0E xx
1 1 1 1 0 0 0 0 0F xx
0 0 0 0 1 0 0 0 10 xx
1 0 0 0 1 0 0 0 11 xx
0 1 0 0 1 0 0 0 12 xx
1 1 0 0 1 0 0 0 13 xx
0 0 1 0 1 0 0 0 14 xx
1 0 1 0 1 0 0 0 15 xx
0 1 1 0 1 0 0 0 16 xx
1 1 1 0 1 0 0 0 17 xx
0 0 0 1 1 0 0 0 18 xx
1 0 0 1 1 0 0 0 19 xx
0 1 0 1 1 0 0 0 1A xx
1 1 0 1 1 0 0 0 1B xx
0 0 1 1 1 0 0 0 1C xx
1 0 1 1 1 0 0 0 1D xx
0 1 1 1 1 0 0 0 1E xx

1 1 1 1 1 0 0 0 1F xx
0 0 0 0 0 1 0 0 20 xx
1 0 0 0 0 1 0 0 21 xx
0 1 0 0 0 1 0 0 22 xx
1 1 0 0 0 1 0 0 23 xx
0 0 1 0 0 1 0 0 24 xx
1 0 1 0 0 1 0 0 25 xx
0 1 1 0 0 1 0 0 26 xx
1 1 1 0 0 1 0 0 27 xx
0 0 0 1 0 1 0 0 28 xx
1 0 0 1 0 1 0 0 29 xx
0 1 0 1 0 1 0 0 2A xx
1 1 0

1 0 1 0 0 2

B xx

0 0 1 1 0 1 0 0 2C xx
1 0 1 1 0 1 0 0 2D xx
0 1 1 1 0 1 0 0 2E xx
1 1 1 1 0 1 0 0 2F xx
0 0 0 0 1 1 0 0 30 xx
1 0 0 0 1 1 0 0 31 xx
0 1 0 0 1 1 0 0 32 xx
1 1 0 0 1 1 0 0 33 xx
0 0 1 0 1 1 0 0 34 xx
1 0 1 0 1 1 0 0 35 xx
0 1 1 0 1 1 0 0 36 xx
1 1 1 0 1 1 0 0 37 xx
0 0 0 1 1 1 0 0 38 xx
1 0 0 1 1 1 0 0 39 xx
0 1 0 1 1 1 0 0 3A xx
1 1 0 1 1 1 0 0 3B xx
0 0 1 1 1 1 0 0 3C xx
1 0 1 1 1 1 0 0 3D xx
0 1 1 1 1 1 0 0 3E xx
1 1 1 1 1 1 0 0 3F xx

* Displayed only when the request code is 553.

0: OFF 1: ON

OUT

Display

8 9 10 11 12 13 14 15
0 0 0 0 0 0 1 0 40 xx
1 0 0 0 0 0 1 0 41 xx
0 1 0 0 0 0 1 0 42 xx
1 1 0 0 0 0 1 0 43 xx
0 0 1 0 0 0 1 0 44 xx
1 0 1 0 0 0 1 0 45 xx
0 1 1 0 0 0 1 0 46 xx
1 1 1 0 0 0 1 0 47 xx
0 0 0 1 0 0 1 0 48 xx
1 0 0 1 0 0 1 0 49 xx
0 1 0 1 0 0 1 0 4A xx
1 1 0 1 0 0 1 0 4B xx
0 0 1 1 0 0 1 0 4C xx
1 0 1 1 0 0 1 0 4D xx
0 1 1 1 0 0 1 0 4E xx
1 1 1 1 0 0 1 0 4F xx
0 0 0 0 1 0 1 0 50 xx
1 0 0 0 1 0 1 0 51 xx
0 1 0 0 1 0 1 0 52 xx
1 1 0 0 1 0 1 0 53 xx
0 0 1 0 1 0 1 0 54 xx
1 0 1 0 1 0 1 0 55 xx
0 1 1 0 1 0 1 0 56 xx
1 1 1 0 1 0 1 0 57 xx
0 0 0 1 1 0 1 0 58 xx
1 0 0 1 1 0 1 0 59 xx
0 1 0 1 1 0 1 0 5A xx
1 1 0 1 1 0 1 0 5B xx
0 0 1 1 1 0 1 0 5C xx
1 0 1 1 1 0 1 0 5D xx
0 1 1 1 1 0 1 0 5E xx
1 1 1 1 1 0 1 0 5F xx
0 0 0 0 0 1 1 0 60 xx
1 0 0 0 0 1 1 0 61 xx
0 1 0 0 0 1 1 0 62 xx
1 1 0 0 0 1 1 0 63 xx
0 0 1 0 0 1 1 0 64 xx
1 0 1 0 0 1 1 0 65 xx
0 1 1 0 0 1 1 0 66 xx
1 1 1 0 0 1 1 0 67 xx
0 0 0 1 0 1 1 0 68 xx
1 0 0 1 0 1 1 0 69 xx
0 1 0 1 0 1 1 0 6A xx
1 1 0

1 0 1 1 0 6

B xx

0 0 1 1 0 1 1 0 6C xx
1 0 1 1 0 1 1 0 6D xx
0 1 1 1 0 1 1 0 6E xx
1 1 1 1 0 1 1 0 6F xx
0 0 0 0 1 1 1 0 70 xx
1 0 0 0 1 1 1 0 71 xx
0 1 0 0 1 1 1 0 72 xx
1 1 0 0 1 1 1 0 73 xx
0 0 1 0 1 1 1 0 74 xx
1 0 1 0 1 1 1 0 75 xx
0 1 1 0 1 1 1 0 76 xx
1 1 1 0 1 1 1 0 77 xx
0 0 0 1 1 1 1 0 78 xx
1 0 0 1 1 1 1 0 79 xx
0 1 0 1 1 1 1 0 7A xx
1 1 0 1 1 1 1 0 7B xx
0 0 1 1 1 1 1 0 7C xx
1 0 1 1 1 1 1 0 7D xx
0 1 1 1 1 1 1 0 7E xx
1 1 1 1 1 1 1 0 7F xx

OCH570

43

0: OFF (open) 1: ON (short)

IN

Display

1 2 3 4 5 6 7 8
0 0 0 0 0 0 0 0 00 00
1 0 0 0 0 0 0 0 00 01
0 1 0 0 0 0 0 0 00 02
1 1 0 0 0 0 0 0 00 03
0 0 1 0 0 0 0 0 00 04
1 0 1 0 0 0 0 0 00 05
0 1 1 0 0 0 0 0 00 06
1 1 1 0 0 0 0 0 00 07
0 0 0 1 0 0 0 0 00 08
1 0 0 1 0 0 0 0 00 09
0 1 0 1 0 0 0 0 00 0A
1 1 0 1 0 0 0 0 00 0B
0 0 1 1 0 0 0 0 00 0C
1 0 1 1 0 0 0 0 00 0D
0 1 1 1 0 0 0 0 00 0E
1 1 1 1 0 0 0 0 00 0F
0 0 0 0 1 0 0 0 00 10
1 0 0 0 1 0 0 0 00 11
0 1 0 0 1 0 0 0 00 12
1 1 0 0 1 0 0 0 00 13
0 0 1 0 1 0 0 0 00 14
1 0 1 0 1 0 0 0 00 15
0 1 1 0 1 0 0 0 00 16
1 1 1 0 1 0 0 0 00 17
0 0 0 1 1 0 0 0 00 18
1 0 0 1 1 0 0 0 00 19
0 1 0 1 1 0 0 0 00 1A
1 1 0 1 1 0 0 0 00 1B
0 0 1 1 1 0 0 0 00 1C
1 0 1 1 1 0 0 0 00 1D
0 1 1 1 1 0 0 0 00 1E
1 1 1 1 1 0 0 0 00 1F

0 0 0 0 0 1 0 0 00 20
1 0 0 0 0 1 0 0 00 21
0 1 0 0 0 1 0 0 00 22
1 1 0 0 0 1 0 0 00 23
0 0 1 0 0 1 0 0 00 24
1 0 1 0 0 1 0 0 00 25
0 1 1 0 0 1 0 0 00 26
1 1 1 0 0 1 0 0 00 27
0 0 0 1 0 1 0 0 00 28
1 0 0 1 0 1 0 0 00 29
0 1 0 1 0 1 0 0 00 2A
1 1 0

1 0 1 0 0 00

2B
0 0 1 1 0 1 0 0 00 2C
1 0 1 1 0 1 0 0 00 2D
0 1 1 1 0 1 0 0 00 2E
1 1 1 1 0 1 0 0 00 2F
0 0 0 0 1 1 0 0 00 30
1 0 0 0 1 1 0 0 00 31
0 1 0 0 1 1 0 0 00 32
1 1 0 0 1 1 0 0 00 33
0 0 1 0 1 1 0 0 00 34
1 0 1 0 1 1 0 0 00 35
0 1 1 0 1 1 0 0 00 36
1 1 1 0 1 1 0 0 00 37
0 0 0 1 1 1 0 0 00 38
1 0 0 1 1 1 0 0 00 39
0 1 0 1 1 1 0 0 00 3A
1 1 0 1 1 1 0 0 00 3B
0 0 1 1 1 1 0 0 00 3C
1 0 1 1 1 1 0 0 00 3D
0 1 1 1 1 1 0 0 00 3E
1 1 1 1 1 1 0 0 00 3F

Input signal display (Request code: 176/554)

Please refer to Table 1 on relevant wiring diagram whilst using the following.

0: OFF (open) 1: ON (short)

IN

Display

1 2 3 4 5 6 7 8
0 0 0 0 0 0 1 0 00 40
1 0 0 0 0 0 1 0 00 41
0 1 0 0 0 0 1 0 00 42
1 1 0 0 0 0 1 0 00 43
0 0 1 0 0 0 1 0 00 44
1 0 1 0 0 0 1 0 00 45
0 1 1 0 0 0 1 0 00 46
1 1 1 0 0 0 1 0 00 47
0 0 0 1 0 0 1 0 00 48
1 0 0 1 0 0 1 0 00 49
0 1 0 1 0 0 1 0 00 4A
1 1 0 1 0 0 1 0 00 4B
0 0 1 1 0 0 1 0 00 4C
1 0 1 1 0 0 1 0 00 4D
0 1 1 1 0 0 1 0 00 4E
1 1 1 1 0 0 1 0 00 4F
0 0 0 0 1 0 1 0 00 50
1 0 0 0 1 0 1 0 00 51
0 1 0 0 1 0 1 0 00 52
1 1 0 0 1 0 1 0 00 53
0 0 1 0 1 0 1 0 00 54
1 0 1 0 1 0 1 0 00 55
0 1 1 0 1 0 1 0 00 56
1 1 1 0 1 0 1 0 00 57
0 0 0 1 1 0 1 0 00 58
1 0 0 1 1 0 1 0 00 59
0 1 0 1 1 0 1 0 00 5A
1 1 0 1 1 0 1 0 00 5B
0 0 1 1 1 0 1 0 00 5C
1 0 1 1 1 0 1 0 00 5D
0 1 1 1 1 0 1 0 00 5E
1 1 1 1 1 0 1 0 00 5F
0 0 0 0 0 1 1 0 00 60
1 0 0 0 0 1 1 0 00 61
0 1 0 0 0 1 1 0 00 62
1 1 0 0 0 1 1 0 00 63
0 0 1 0 0 1 1 0 00 64
1 0 1 0 0 1 1 0 00 65
0 1 1 0 0 1 1 0 00 66
1 1 1 0 0 1 1 0 00 67
0 0 0 1 0 1 1 0 00 68
1 0 0 1 0 1 1 0 00 69
0 1 0 1 0 1 1 0 00 6A
1 1 0

1 0 1 1 0 00

6B
0 0 1 1 0 1 1 0 00 6C
1 0 1 1 0 1 1 0 00 6D
0 1 1 1 0 1 1 0 00 6E
1 1 1 1 0 1 1 0 00 6F
0 0 0 0 1 1 1 0 00 70
1 0 0 0 1 1 1 0 00 71
0 1 0 0 1 1 1 0 00 72
1 1 0 0 1 1 1 0 00 73
0 0 1 0 1 1 1 0 00 74
1 0 1 0 1 1 1 0 00 75
0 1 1 0 1 1 1 0 00 76
1 1 1 0 1 1 1 0 00 77
0 0 0 1 1 1 1 0 00 78
1 0 0 1 1 1 1 0 00 79
0 1 0 1 1 1 1 0 00 7A
1 1 0 1 1 1 1 0 00 7B
0 0 1 1 1 1 1 0 00 7C
1 0 1 1 1 1 1 0 00 7D
0 1 1 1 1 1 1 0 00 7E
1 1 1 1 1 1 1 0 00 7F

OCH570

44

Indoor unit only operation

Indoor unit

Necessary

Heat pump

Not necessary

Main controller Necessary
DIP switch setting Electric heater

SW4-4 ON, SW4-5 ON

Boiler
SW4-4 ON, SW4-6 ON

Setting range for ow temp. 25 - 60 °C Selectable

Setting range for tank temp. 40 - 60 °C Selectable

Indoor unit only operation

In indoor unit only operation, an operation without connecting outdoor unit is possible.

When in Indoor unit only operation the main control has control functions.

<Heater>

Heating for DHW and space heating is provided by the heater.

• Activating indoor unit only operation mode
To activate indoor unit only operation see the following:

1. Switch OFF the breaker for the outdoor unit (or both breakers if cylinder powered independently).

2. Change DIP switch SW4-4 and SW4-5 to ON.

3. Switch ON the breaker(s).

4. Indoor unit only operation is now activated.

• Deactivating indoor unit only operation mode
To deactivate indoor unit only operation see the following:

1. Switch OFF the breaker for the outdoor unit (or both breakers if cylinder powered independently).

2. Change DIP switch SW4-4 and SW4-5 to OFF.

3. Switch ON the breaker(s).

4. Indoor unit only operation is now deactivated.

<Boiler>

Heating for space heating is provided by the boiler.

• Activating indoor unit only operation mode
To activate indoor unit only operation see the following:

1. Switch OFF the breaker for the outdoor unit (or both breakers if cylinder powered independently).

2. Change DIP switch SW4-4 and SW4-6 to ON.

3. Switch ON the breaker(s).

4. Indoor unit only operation is now activated.

• Deactivating indoor unit only operation mode
To deactivate indoor unit only operation see the following:

1. Switch OFF the breaker for the outdoor unit (or both breakers if cylinder powered independently).

2. Change DIP switch SW4-4 and SW4-6 to OFF.

3. Switch ON the breaker(s).

4. Indoor unit only operation is now deactivated.

Emergency operation

In emergency operation, an operation without connecting outdoor unit and main controller is possible.
When in Emergency operation the main control has NO control functions.
Space heating ow temp. is restarted 40 °C and DHW tank temp. is restricted 50 °C. *1

<Heater>

Heating for DHW and space heating is provided by the heater.

• Activating emergency operation mode
To activate emergency operation see the following:

1. Switch OFF the breaker for the outdoor unit (or both breakers if cylinder powered independently).

2. Change DIP switch SW4-5 to ON.

3. Switch ON the breaker(s).

4. Emergency operation is now activated.

• Deactivating emergency operation mode
To deactivate emergency operation see the following:

1. Switch OFF the breaker for the outdoor unit (or both breakers if cylinder powered independently).

2. Change DIP switch SW4-5 to OFF.

3. Switch ON the breaker(s).

4. Emergency operation is now deactivated.

<Boiler>

Heating for space heating is provided by the boiler.

• Activating emergency operation mode
To activate emergency operation see the following:

1. Switch OFF the breaker for the outdoor unit (or both breakers if cylinder powered independently).

2. Change DIP switch SW4-6 to ON.

3. Switch ON the breaker(s).

4. Emergency operation is now activated.

• Deactivating emergency operation mode
To deactivate emergency operation see the following:

1. Switch OFF the breaker for the outdoor unit (or both breakers if cylinder powered independently).

2. Change DIP switch SW4-6 to OFF.

3. Switch ON the breaker(s).

4. Emergency operation is now deactivated.

WARNING
Do not attempt to change the DIP switches whilst the breaker(s) are ON as this could result in
ELECTROCUTION.

Emergency operation

Indoor unit

Necessary

Heat pump

Not necessary

Main controller Not necessary

DIP switch setting

Electric heater
SW4-5 ON

Boiler
SW4-6 ON

Setting range for ow temp.

Fixed at 40 °C

Setting range for tank temp.

Fixed at 50 °C *1

*1 Default setting is 50 °C. Once system has started running,

emergency operation runs at the latest set temp.

OCH570

45

TROUBLESHOOTING

10

10-1. Troubleshooting

<Summary of self diagnosis based on Error Codes and Service Procedures>

Present and past Error codes are logged and displayed on the main controller or control board of the outdoor unit.
Please refer to the table below and subsequent explanations to diagnose and remedy typical problems that may occur in the eld.

Unit Condition Error Code Action

Reoccurring problem

Displayed Use table 10-4. "Self diagnosis and action" to identify fault and correct.

Not Displayed Use table 10-5. "Troubleshooting by inferior phenomena" to identify fault and correct.

Non reoccurring problem Logged 1. Check temporary causes of defects such as the operation of safety devices on the refrigerant/water

circuit including compressor, poor wiring, electrical noise etc. Re-check the symptom and the instal­lation environment, refrigerant amount (Split systems only), weather conditions at time of fault etc.

2. Reset Error code logs, Service the unit and restart system.

Not Logged

1. Recheck the abnormal symptom

2. Identify cause of problem and take corrective action according to Table 10-5. "Troubleshooting by
inferior phenomena"

3. If no obvious problem can be found continue to operate the unit.

NOTE

Electricalcomponentsshouldonlybereplacedasanaloption.PleasefollowinstructionsinTables10-4.and10-5.ErrorCodesandInferiorPhenomena

fully before resorting to replacing parts.

10-2. Test Run

Before a test run

• After installation of outdoor unit, pipework and electrical wiring, recheck that there is no water leakage, loosened connections or miswiring.

• Measure impedance between the ground and the power supply terminal block (L,N) on the outdoor and indoor units with suitable (500V) ohmmeter. Resistance
should be ≥ 1.0MΩ .

• Read the Installation and Operation Manuals fully especially the safety requirements before carrying out any test runs.

10-3. Malfunction diagnosis method by main controller

If during start up or operation a malfunction occurs the error code screen may be displayed on the main controller.
The error code screen shows the following; code, unit, ref. address, and telephone number of installer (only if previously entered by the installer)
Please not in the case of some malfunctions an error code is not generated please refer to table 10-5. for more details.

To reset

1. To reset the main controller press F4 button (Reset).

2. Then press F3 (Yes) to conrm.

OCH570

46

10-4. Self diagnosis and action

Check if DIP SW is set correctly. (Refer to Section 6-7.)

Error code Title and display conditions Possible Cause Diagnosis and action

L3 Circulation water temperature overheat

protection

<DHW/Heating/LP/FS/OS>

Error code displayed when THW1 detects a
temp. ≥ 80ºC for 10 consecutive seconds or
THW2 detects a temp. ≥ 80ºC for 10 consecutive

seconds.

DHW : Domestic hot water mode
Heating : Heating mode
LP : Legionella prevention mode
FS : Freeze stat

OS : Operation stop
TH1A/B : Room temp. thermistor

TH2 : Liquid refrigerant temp. thermistor
THW1 : Flow water temp. thermistor
THW2 : Return water temp. thermistor
THW5 : Tank water temp. thermistor

THW6 :

Zone 1 ow water temperature thermistor

THW7 :

Zone 1 return water temperature thermistor

THW8 :

Zone 2 ow water temperature thermistor

THW9 :

Zone 2 return water temperature thermistor

THWB1 :

Boiler flow water temperature thermistor

THWB2 :

Boiler return water temperature thermistor

1.

Insufcient system head

1

Refer to table in section 10-6. to determine
if system pump meets requirements.
If more head required either add an pump

of the same size or replace existing pump
with capacity model.

See 11. DISASSEMBLY PROCEDURE for

how to replace pump.

2.

Reduced ow in primary water circuit
Due to 1 or more of the following;
Faulty pump, insufcient air purge,
blocked strainer, leak in water circuit.

2.

Check circulation pump (See 10-6. for how

to check).

Open purge valve to remove trapped air.
Check the strainer for blockages.
Check the primary water circuit for leaks.
Check that the flow amount is within the
recommended range.

3.

Valve operation fault

3.

Check valves on primary water circuit are

installed level.

4.

2-way valve (local supply) actuator

fault

4.

Electrically test to determine fault

5.

3-way valve actuator fault

5.

1) Electrically test to determine fault.

2) Operate 3-way valve manually using

the main remote controller. (Refer to
<Manual operation> in 9-4).

3) Replace 3-way valve coil.

4)

Replace 3-way valve. (Refer to Procedure

6 in “11. DISASSEMBLY PROCEDURE.”

6.

Booster heater relay (BHC1, BHC2,

BHCP) operating fault

6.

Electrically test the relays (BHC1, BHC2,
BHCP) to determine fault.

See 10-6. for how to check.

7.

Power supply voltage increase

7.

Check the supply voltage.

8.

THW1 or THW5 has become de­tached from its holder.

8.

Visually inspect location and reattach as
necessary.

9.

THW1 or THW2 fault

9.

Check resistance of thermistor against ta­ble in section 10-6.
Compare FTC detected temperature to
hand held detector.

10.

FTC board failure

10.

Replace board.

L4

Tank water temperature overheat protection

<DHW/Heating/LP/FS/OS>
Error code display when THW5 detects a
temp. ≥ 75ºC for 10 consecutive seconds.

1.

3-way valve actuator fault

1.

1) Electrically test to determine fault.

2) Operate 3-way valve manually using

the main remote controller. (Refer to
<Manual operation> in 9-4).

3) Replace 3-way valve coil.

4) Replace 3-way valve. (Refer to Procedure

6 in “11. DISASSEMBLY PROCEDURE.”

2.

Immersion heater relay (IHC) operat-

ing fault

2.

Check immersion heater relay (IHC).

3.

THW5 fault

3.

Check resistance of thermistor against ta­ble in section 10-6.
Compare FTC detected temperature to
hand held detector.

4.

FTC board failure

4.

Replace board.

OCH570

47

Error code Title and display conditions Possible Cause Diagnosis and action

P1/P2/L5/LD

Indoor unit temperature thermistor failure

* The thermistors subject to failure can be checked

in “Request code: 567” in “Running information

<DHW/Heating/LP/FS/OS>
Error code displayed when thermistor is at open or

short (see table).

Exceptions
Error code will not be displayed for TH2; During

defrost and for 10 minutes after defrost operation.

Error code

Thermistor

Open detection Short detection

Symbol Name
P1 TH1A/TH1B Room temperature thermisitor -39ºC or below 88.5ºC or above
P2 TH2 Liquid temperature thermisitor -39ºC or below 88.5ºC or above

L5

THW1 Flow water temperature thermisitor -39ºC or below 88.5ºC or above
THW2 Return water temperture thermisitor -39ºC or below 88.5ºC or above
THW5 Tank water temperture thermisitor -39ºC or below 88.5ºC or above
THW6

Zone 1 ow water temperature thermistor

-39ºC or below 88.5ºC or above

THW7

Zone 1 return water temperature thermistor

-39ºC or below 88.5ºC or above

THW8

Zone 2 ow water temperature thermistor

-39ºC or below 88.5ºC or above

THW9

Zone 2 return water temperature thermistor

-39ºC or below 88.5ºC or above

LD

THWB1

Boiler flow water temperature thermistor

-40ºC or below 140ºC or above

THWB2

Boiler return water temperature thermistor

-40ºC or below 140ºC or above

1. Connector/terminal wire has become
detached or loose wiring.

1. Visually check the terminals and connec­tions and reattaches appropriate.

2. Thermistor fault 2. Check resistance of thermistor against
table in section 10-6.
Compare FTC detected temperature to
hand held detector.

3. FTC board failure 3. Replace board.

4. The thermistor on the wireless remote

controller or the main remote control-

ler may be defective. (when Room
temp. is chosen for the Heating opera­tion and when Main Controller or

Room RC 1-8 is chosen for the Room

Sensor setting in the Initial setting)

4. Replace wireless remote controller or main
remote controller.

5. Incorrect setting of the DIP switch(es) 5. Check the DIP switch setting(s).

L6

Circulation water freeze protection
<DHW/Heating/LP/FS/OS>

Error code displayed when THW1 detects a
temp. ≤ 1ºC for 10 consecutive seconds or
THW2 detects a temp. ≤ 3ºC for 10 consecutive

seconds.

Exception
Error code will not be displayed if;

FS function is disabled,

For 10 minutes after water circulation pump1 is
switched on.

1. Insufcient system head 1. Refer to table in section 10-6. to determine
if system pump meets requirements.
If more head required either add an pump

of the same size or replace existing pump
with capacity model.

See 11. DISASSEMBLY PROCEDURE for

how to replace pump.

2. Reduced ow in primary water circuit

Due to 1 or more of the following;
Faulty pump, insufcient air purge,
blocked strainer, leak in water circuit

2. Check circulation pump (See 10-6. for how
to check).

Open purge valve to remove trapped air.
Check the strainer for blockages.
Check the primary water circuit for leaks.
Check that the ow amount is within the
recommended range.

3. Valve operation fault 3. Check valves on primary water circuit are
installed level.

4. 2-way valve (local supply) actuator

fault

4. Electrically test to determine fault.

5. 3-way valve actuator fault 5. 1) Electrically test to determine fault.

2) Operate 3-way valve manually using the

main remote controller. (Refer to
<Manual operation> in 9-4).

3) Replace 3-way valve coil.

4) Replace 3-way valve. (Refer to Procedure

6 in “11. DISASSEMBLY PROCEDURE.”

6. THW1 has become detached from its

holder.

6. Visually inspect location and reattach as
necessary.

7. THW1 or THW2 fault 7. Check resistance of thermistor against table
in section 10-6.
Compare FTC detected temperature to
hand held detector.

8. FTC board failure 8. Replace board.

OCH570

48

Error code Title and display conditions Possible Cause Diagnosis and action

L8 Heating operation error

* “3” is displayed in “Request code: 567” in “Run-

ning information”.
<Heating/FS>
If a), b) and c) occur, L8 is displayed;

a)

No change on THW1 and THW5

(under 1 °C for 20 minutes from unit starts
operation)

b) No change on THW1

(under 1 °C for 10 minutes from booster heater
starts operation)

c) THW1 - THW2 < -5 °C

(for 10 minutes continuously)

1. THW1 has become detached from its
holder.

1. Visually inspect location and reattach as
necessary.

2. Booster heater fault 2. Electrically test to determine fault.

See 10-6. for how to check.

3. THW1 or THW2 or THW5 fault 3. Check resistance of thermistor against
table in section 10-6.
Compare FTC detected temperature to
hand held detector.

4. FTC board failure 4. Replace board.

Heating operation error

* “a” is displayed in “Request code: 567” in

“Running information”.

1. THW6 has become detached from its

holder.

1. Visually inspect location and reattach as
necessary.

2. THW6 or THW7 fault 2. Check resistance of thermistor against
table in section 10-6.
Compare FTC detected temperature to
hand held detector.

3. FTC board failure 3. Replace board.

Heating operation error

* “c” is displayed in “Request code: 567” in

“Running information”.

1. THW8 has become detached from its

holder.

1. Visually inspect location and reattach as
necessary.

2. THW8 or THW9 fault 2. Check resistance of thermistor against
table in section 10-6.
Compare FTC detected temperature to
hand held detector.

3. FTC board failure 3. Replace board.

L9

Lowprimarycircuit(Heatsourceside)ow
ratedetectedbyowswitch

* “1” is displayed in “Request code: 569” in “Run-

ning information”.
<DHW/Heating/LP/FS>
Error code displayed when ow sensor detects
low ow rate for 10 seconds.

Exception
For 1 minute after water circulation pump1 is
switched on.

1. Insufcient system head 1. Refer to table in section 10-6. to determine
if system pump meets requirements.
If more head required either add an pump

of the same size or replace existing pump
with capacity model.

See 11. DISASSEMBLY PROCEDURE for

how to replace pump.

2. Reduced ow in primary water circuit

Due to 1 or more of the following;
Faulty pump, insufcient air purge,
blocked strainer, leak in water circuit.

2. Check circulation pump (See 10-6. for how
to check).

Open purge valve to remove trapped air.
Check the strainer for blockages.
Check the primary water circuit for leaks.
Check that the ow amount is within the
recommended range.

3. Valve operation fault 3. Check valves on primary water circuit are
installed level.

4.

2-way valve (local supply) actuator

fault

4. Electrically test to determine fault.

5. Connector/terminal wire has become

detached or loose wiring.

5. Visually check the CN2F connector and
IN2 terminal and reattach if necessary.

6. Flow switch fault 6. Electrically test to determine fault.

See 10-6. for how to check.

7. Incorrect setting of the SW2-2 7. Check the SW2-2 setting.

8. FTC board failure 8. Replace board.

Lowprimarycircuit(Zone1side)owrate
detectedbyowswitch/owsensor

* “2” is displayed in “Request code: 569” in “Run-

ning information”.

1. Insufcient system head 1. If more head required either add an pump
of the same size or replace existing pump .

2. Reduced ow in primary water circuit

Due to 1 or more of the following;
Faulty pump, insufcient air purge,
blocked strainer, leak in water circuit.

2. Check circulation pump (See 10-6. for how
to check).

Open purge valve to remove trapped air.
Check the strainer for blockages.
Check the primary water circuit for leaks.
Check that the ow amount is within the
recommended range.

3. Terminal wire has become detached
or loose wiring.

3. Visually check the IN3 terminal and reat­tach if necessary.

4. Flow switch fault 4. Electrically test to determine fault.

5. Incorrect setting of the SW3-2 5. Check the SW3-2 setting.

6. FTC board failure 6. Replace board.

OCH570

49

Error code Title and display conditions Possible Cause Diagnosis and action

L9 Lowprimarycircuit(Zone2side)owrate

detectedbyowswitch

* “3” is displayed in “Request code: 569” in

“Running information”.

1. Insufcient system head 1. If more head required either add an pump
of the same size or replace existing pump.

2. Reduced ow in primary water circuit

Due to 1 or more of the following;
Faulty pump, insufcient air purge,
blocked strainer, leak in water circuit

2. Check circulation pump (See 10-6. for how
to check).

Open purge valve to remove trapped air.
Check the strainer for blockages.
Check the primary water circuit for leaks.
Check that the ow amount is within the
recommended range.

3. Terminal wire has become detached
or loose wiring.

3. Visually check the IN7 terminal and
reattach if necessary.

4. Flow switch fault 4. Electrically test to determine fault.

5. Incorrect setting of the SW3-3 5. Check the SW3-3 setting.

6. FTC board failure 6. Replace board.

LC Boiler circulation water temperature overheat

protection

<DHW/Heating/LP/FS/OS>
Error code displayed when THWB1 detects a
temp. ≥80ºC for 10 consecutive seconds or
THWB2 detects a temp. ≥80ºC for 10 consecu-

tive seconds

1. The set temperature for Boiler is too

high.

1. Check if the set temperature for Boiler for

heating exceeds the restriction. (See the
manual for the thermistors "PAC-TH011HT­E")

2. Flow rate of the heating circuit from the
boiler may be reduced.

2. Check for

• water leakage

• strainer blockage

• water circulation pump function.

LD Boiler temperature thermistor (THWB1, THWB2)

failure

Refer to error codes (P1/P2/L5/LD).

LE Boiler operation error

<Heating>
Boiler is running and THW6 detects a
temperature <30ºC for consecutive 60 minutes.

1. THW6 has become detached from its
holder.

1. Visually inspect location and reattach as
necessary.

2. Incorrect wiring between FTC (OUT10)
and the boiler.

2. See the manual of the thermistors

"PAC-TH011HT-E".

3. Boiler fuel has run out or the system is
OFF.

3. Check the status of the boiler.

4. Boiler failure 4. Check the status of the boiler.

5. FTC board failure 5. Replace board.

LF Flow sensor failure Check ow sensor cable for damage or loose con-

nections.

LH Boiler circulation water freeze protection Flow rate of the heating circuit from the boil-

er may be reduced.

Check for

• water leakage

• strainer blockage

• water circulation pump function.

LJ

DHW operation error (type of external plate HEX)

1. DHW tank water temp. thermistor

(THW5) has become detached from its
holder.

2. Flow rate of the sanitary circuit may be

reduced.

1. Check for disconnection of DHW tank water
temp. thermistor (THW5).

2. Check for water circulation pump function.

LL Setting errors of DIP switches on FTC control

board

Incorrect setting of DIP switches.

1. Boiler operation 1. For boiler operation, check that DIP SW1-1
is set to ON (With Boiler) and DIP SW2-6 is

set to ON (With Mixing Tank).

2. 2-zone temperature control 2. For 2-zone temperature control, check DIP
SW2-7 is set to ON (2-zone) and DIP
SW2-6 is set to ON (With Mixing Tank).

P1 Indoor unit temperature thermistor (TH1) failure Refer to error codes (P1/P2/L5/LD).

P2 Indoor unit temperature thermistor (TH2) failure Refer to error codes (P1/P2/L5/LD).

P6

Anti-freeze protection of plate heat exchanger
<Defrosting>
THW2 detects a temperature ≤15ºC and TH2
detects a temperature ≤−16ºC for consecutive 10

seconds.

1. Reduced water ow 1. and 2.

• Clogged lter

• Leakage of water

Check water piping.

2. Low temperature

• Low load

• Inlet water is cold

3. Defective water pump 3. Check water pump.

4. Leakage or shortage of refrigerant 4. Correct to proper amount of refrigerant.

5. Malfunction of linear expansion valve 5. Check linear expansion valve.

OCH570

50

Error code Title and display conditions Possible Cause Diagnosis and action

E0/E4 Main controller communication failure

(Reception error)

Error code E0 is displayed if main controller does

not receive any signal from the indoor unit for ref.
address "0" for 3 minutes.

Error code E4 is displayed if indoor unit does not
receive any data from the main controller for 3

mins or indoor unit does not receive any signal

from the main controller for 2 minutes.

1. Contact failure with transmission cable 1. Check connection cable for damage or
loose connections at the FTC and main
controller terminals.

2. Wiring procedure not observed.

(Cable length/cable diameter/number

of indoor units/number of main
controllers)

2. Check main controller and FTC common

wiring max cable length 500 m.

Only use 2 core cable.
Only connect 1 main controller to 1 FTC
indoor unit board.

3. Fault on the indoor unit FTC board

section controlling Ref. address "0"

3. to 5.

If the problem is not solved by the above
measures then:

Turn the power to the indoor unit OFF and

then ON.

Power to both the indoor unit and outdoor
units should be switched OFF then ON.
(This may require switching 1 or 2 breakers
depending if the unit is powered indepen-

dently from the outdoor unit).
If the E4 code is still displayed the FTC and/
or the main controller circuit board should
be replaced.

4. Fault with the main controller circuit

board

5. Electrical noise causes interference

with transmission/reception of data for

main controller.

E3/E5 Main controller communication failure

(Transmission error)

Error code E3 is displayed if the main controller

an not nd an empty transmission path and thus

fails to transmit for 6 secs or the data received by

the main controller is different to what was sent

(by the main controller) 30 consecutive times.

Error code E5 is displayed if the FTC can not nd

an empty transmission path for 3 minutes and
thus cannot transmit or the data sent by the FTC

is different to what was expected 30 consecutive

times.

1. 2 or more main controllers have been

connected to the FTC.

1. Only connect 1 main controller to 1 FTC
indoor unit board.

2. Fault with main controller transmission/

receiving circuit board

2. to 4.

Turn the power to the indoor unit OFF and

then ON.

Power to both the indoor unit and outdoor
units should be switched OFF then ON.
(This may require switching 1 or 2 breakers
depending if the unit is powered indepen-

dently from the outdoor unit).
If the E3/E5 code is still displayed the FTC
and/or the main controller circuit board
should be replaced.

3. Fault with the main controller circuit
board

4. Electrical noise causes interference

with transmission/reception of data for

main controller.

E6 Indoor/outdoor communication failure

(Reception error)

Error code E6 is displayed if after the power is
switched ON to the indoor unit, the FTC board
does not receive any signal or the signal received

is not complete for 6 minutes, or after a period of
operation the FTC board does not receive any

signal or the signal received is not complete for 3

minutes.

* Check the LED display on the outdoor unit

circuit board.
(Connect the A-control service tool, PAC­SK52ST to test.) Refer to the outdoor unit ser-

vice manual for explanation of EA-EC codes.

1. Contact failure/short circuit/miswiring 1. Check the connections on the indoor and

outdoor units have not become loose and

that the connecting cable is not damaged.

2. Fault with outdoor unit transmission/
receiving circuit board

2. to 4.

Turn the power to the indoor unit OFF and

then ON.

Power to both the indoor unit and outdoor
units should be switched OFF then ON.
(This may require switching 1 or 2 breakers
depending if the unit is powered indepen-

dently from the outdoor unit).
If the E6 code is still displayed the FTC and/
or the outdoor unit circuit board should be
replaced.

3. Fault with FTC transmission/receiving
circuit board

4. Electrical noise causes interference

with FTC-Outdoor unit transmission

cable.

E7 Indoor/outdoor communication failure

(Transmission error)

Error code E7 is displayed if despite the FTC

board sending signal "0", signal "1" is received

30 consecutive times.

1. Fault with FTC transmission/receiving
circuit board

1. to 3.

Turn the power to the indoor unit OFF and

then ON.

Power to both the indoor unit and outdoor
units should be switched OFF then ON.
(This may require switching 1 or 2 breakers
depending if the unit is powered indepen-

dently from the outdoor unit).
If the E7 code is still displayed the FTC cir­cuit board should be replaced.

2. Electrical noise causes interference

with power supply.

3. Electrical noise causes interference
with FTC-outdoor unit transmission ca­ble.

E1/E2

Main controller control board failure

Error code E1 displayed if main controller can not

access it's non volatile (non power dependent)

memory.

Error code E2 is displayed when there is a fault
with the main controller's internal clock.

1. Fault with the main controller circuit
board

1. Replace main controller circuit board.

OCH570

51

Error code Title and display conditions Possible Cause Diagnosis and action

J0 Indoor unit/wireless receiver communication

failure

Error code J0 is displayed when the FTC can not
receive data from the wireless receiver for 1 min-

ute.

1. Connection fault with wireless receiver-
FTC connection

1. Check the connections to the wireless re­ceiver and FTC have not become loose and

that the connecting cable is not damaged.

2. Fault with FTC receiving circuit board 2. to 4.
Turn the power to the indoor unit OFF and

then ON.

Power to both the indoor unit and outdoor
units should be switched OFF then ON.
(This may require switching 1 or 2 breakers
depending if the unit is powered indepen-

dently from the outdoor unit).
If the J0 code is still displayed the FTC and/

or the wireless receiver circuit board should

be replaced.

3. Fault with wireless receiver's transmis-

sion circuit board

4. Electrical noise causes interference

with wireless receiver communication

cable.

J1 to J8

Wireless remote controller/wireless receiver
communication failure
(Reception error)

Error code displayed if wireless receiver receives
no/incomplete data from the wireless remote

controller for 15 consecutive minutes.

The digit after the J refers to the address of the
wireless remote controller that has the error.
E.g. Error code "J3" refers to a communication
fault between the wireless receiver and wireless
remote control with address 3.

1. Battery on wireless remote control may

be at

1 Check and replace the battery if necessary

the wireless remote controller battery.

2. The wireless remote controller is out of

range of the wireless receiver.

2. to 4.

Reposition the wireless remote control

closer to the receiver and perform a
communication test.

For procedure refer to wireless remote

controller installation manual.

If "OK" is displayed then the cause of the
J1 to J8 error was the controller was out of
range of the receiver.
The wireless remote controller should be
installed within range of the receiver.
If "Err" is displayed replace wireless remote
controller with a new controller and perform
the pairing procedure.
If after this procedure the "Err" code is still
displayed the fault is with the receiver unit

(attached to the indoor unit).

The receiver unit should be replaced with a
new part and the original remote control can

be reconnected.

If "OK" is displayed then the fault is with the

remote control and this should be replaced.

3. Fault with wireless remote controller

transmission circuit board

4. Fault with wireless receiver's reception

circuit board

Note: To cancel error codes please switch system off (press button F4 (RESET) on main controller).

OCH570

52

10-5. Troubleshooting by inferior phenomena

No. Fault symptom Possible cause Explanation - Solution

1 Main controller display

is blank.

1. There is no power supply to main
controller.

1. Check LED2 on FTC. (See 6. WIRING DIAGRAM.)
(i) When LED2 is lit.

Check for damage or contact failure of the main controller wiring.

(ii) When LED2 is blinking.

Refer to No. 5 below.

(iii) When LED2 is not lit.

Refer to No. 4 below.

2. Power is supplied to main controller,
however, the display on the main

controller does not appear.

2. Check the following:

• Disconnection between the main controller cable and the FTC control board

• Failure of the main controller if “Please Wait” is not displayed.

• Refer to No. 2 below if “Please Wait” is displayed.

2 “Please Wait” remains

displayed on the main
controller.

1. "Please Wait" is displayed for up to 6
minutes.

1. Normal operation

2. Communication failure between the main
controller and FTC.

2, 3.

Main controller start up checks/procedure.

(i) If “0%” or “50-99%” is displayed below "Please Wait" there is a

communication error between the main controller and the FTC control board.

• Check wiring connections on the main controller.

• Replace the main controller or the FTC control board.

(ii) If “1-49%” is displayed there is a communication error between the outdoor

unit's and FTC's control boards.

• Check the wiring connections on the outdoor unit control board and the FTC

control board.

(Ensure S1 and S2 are not cross-wired and S3 is securely wired with no
damage. (See 7. FIELD WIRING.)

• Replace the outdoor unit's and/or the FTC's control boards.

3. Communication failure between FTC and
outdoor unit.

3 The main screen

appears with a press

of the “ON” button, but
disappears in a second.

The main controller operations do not work
for a while after the settings are changed in

the service menu. This is because the system

takes time to apply the changes.

Normal operation

The indoor unit is applying updated settings made in the service menu. Normal
operation will start shortly.

4 LED2 on FTC is off.

(See 6. WIRING
DIAGRAM.)

When LED1 on FTC is also off. (See 6.
WIRING DIAGRAM.)

<FTC powered via outdoor unit.>

1. The outdoor unit is not supplied at the

rated voltage.

1. Check the voltage across the terminals L and N or L3 and N on the outdoor
power board. (See 7. FIELD WIRING.)

• When the voltage is not 220 to 240V AC, check wiring of the outdoor unit and

of the breaker.

• When the voltage is at 220 to 240V AC, go to “2.” below.

2. Defective outdoor controller circuit board. 2. Check the voltage across the outdoor unit terminals S1 and S2. (See 7. FIELD
WIRING.)

• When the voltage is not 220 to 240V AC, check the fuse on the outdoor
control board and check for faulty wiring.

• When the voltage is 220 to 240V AC, go to “3.” below.

3. FTC is not supplied with 220 to 240V AC. 3. Check the voltage across the indoor unit terminals S1 and S2. (See 7. FIELD
WIRING.)

• When the voltage is not 220 to 240V AC, check FTC-outdoor unit wiring for

faults.

• When the voltage is 220 to 240V AC, go to “4.” below.

4. FTC failure 4. Check the FTC control board.

• Check the fuse on FTC control board.

• Check for faulty wiring.

• If no problem found with the wiring, the FTC control board is faulty.

5. Faulty connector wiring 5. Check the connector wiring.

• When the connectors are wired incorrectly, re-wire the connectors referring to
below. (See 7. FIELD WIRING.)

S1

S2

S3

L

N

CN01

CN01

BLACK

YELLOW

YELLOW

BLACK

Initial settings
(Power

supplied by
outdoor unit)

Cylinder unit
control board

White

OCH570

53

No. Fault symptom Possible cause Explanation - Solution

4. LED2 on FTC is off.
(See 6. WIRING
DIAGRAM)

<FTC powered on independent source>

1. FTC is not supplied with 220 to 240V AC. 1. Check the voltage across the L and N terminals on the indoor power supply
terminal block. (See 7. FIELD WIRING.)

• When the voltage is not 220 to 240V AC, check for faulty wiring to power

supply.

• When the voltage is 220 to 240V AC, go to 2. below.

2. There are problems in the method of

connecting the connectors.

2. Check for faulty wiring between the connectors.

• When the connectors are wired incorrectly re-wire them correctly referring
to below. (See 7. FIELD WIRING and a wiring diagram on the control and
electrical box cover.)

L

N

CN01

CN01

S1

S2

S3

• If no problem found with the wiring, go to 3. below.

3. FTC failure. 3. Check the FTC control board.

• Check the fuse on FTC control board.

• Check for faulty wiring.

• If no problem found with the wiring, the FTC control board is faulty.

When LED1 on FTC is lit. Recheck the refrigerant address setting on the outdoor unit.

Set the refrigerant address to “0”.
(Set refrigerant address using SW1(3 - 6) on outdoor controller circuit board.)

Incorrect setting of refrigerant address for

outdoor unit.

(None of the refrigerant address is set to "0".)

5 LED2 on FTC is

blinking.

(See 6. WIRING
DIAGRAM)

When LED1 is also blinking on FTC . Check for faulty wiring between FTC and outdoor unit.

Faulty wiring between FTC and outdoor unit

When LED1 on FTC is lit.

1. Faulty wiring in main controller

Multiple indoor units have been wired to a
single outdoor unit.

1. Check for faulty wiring in main controller.
The number of indoor units that can be wired to a single outdoor unit is one.
Additional indoor units must be wired individually to a single outdoor unit.

2. Short-circuited wiring in main controller

2.,3.

Remove main controller wires and check LED2 on FTC. (See 6. WIRING

DIAGRAM.)

• If LED2 is blinking check for short circuits in the main controller wiring .

• If LED2 is lit, wire the main controller again and:

- if LED2 is blinking, the main controller is faulty;

- if LED2 is lit, faulty wiring of the main controller has been corrected.

3. Main controller failure

6 LED4 on FTC is off.

(See 6. WIRING
DIAGRAM)

1. SD memory card is NOT inserted into the

memory card slot with correct orientation.

1. Correctly insert SD memory card in place until a click is heard.

2. Not an SD standards compliant memory card. 2. Use an SD standards compliant memory card. (Refer to installation manual,

"5.7 Using SD memory card".)

LED4 on FTC is
blinking.
(See 6. WIRING
DIAGRAM)

1. Full of data. 1. Move or delete data, or replace SD memory card with a new one.

2. Write-protected. 2. Release the write-protect switch.

3. NOT formatted. 3. Refer to installation manual, "5.7 Using SD memory card".

4. Formatted in NTFS le system. 4. FTC is Not compatible with NTFS le system. Use an SD memory card for-

matted in FAT le system.

7 No water at hot tap. 1. Cold main off 1. Check and open stop cock.

2. Strainer (local supply) blocked. 2. Isolate water supply and clean strainer.

8 Cold water at tap. 1. Hot water run out. 1. Ensure DHW mode is operating and wait for DHW tank to re-heat.

2. Prohibit, schedule timer or holiday mode se­lected.

2. Check settings and change as appropriate.

3. Heat pump not working. 3. Check heat pump – consult outdoor unit service manual.

4. Booster heater cut-out trip

ped

. 4. Check booster heater thermostat and press reset button if safe.

Reset button is located on the side of booster heater, covered with white rub­ber cap. See 4. PART NAMES AND FUNCTIONS to nd out its position.

5.

The earth leakage circuit breaker for booster

heater breaker (ECB1) tripped.

5. Check the cause and reset if safe.

6. The booster heater thermal cut-out has

tripped and cannot be reset using the manual

reset button.

6. Check resistance across the thermal cut-out, if open then the connection is

broken and the booster heater will have to be replaced.

Contact your Mitsubishi Electric dealer.

7. Immersion heater cut-out tripped. 7. Check immersion heater thermostat and press reset button, located on im-

mersion heater boss, if safe. If the heater has been operated with no water
inside it may have failed, so please replace it with a new one.

8.

Immersion heater breaker (ECB2) tripped.

8. Check the cause and reset if safe.

9. 3-way valve fault 9. Check plumbing/wiring to 3-way valve.

(i) Manually override 3-way valve using the main controller. (Refer to <Manual

operation> in section 9-4.) If the valve does not still function, go to (ii) be­low.

(ii) Replace 3-way valve coil. If the valve does not still function, go to (iii) be-

low.

(iii) Replace 3-way valve. (Refer to 11. DISASSEMBLY PROCEDURE.)

YELLOW

YELLOW

BLACK

BLACK

Modied settings
(Separate power

supply to the
cylinder unit)

Cylinder unit
control board

White

OCH570

54

No. Fault symptom Possible cause Explanation - Solution

9 Water heating takes

longer.

1. Heat pump not working. 1. Check heat pump – consult outdoor unit service manual.

2. Booster heater cut-out tripped. 2. Check booster heater thermostat and press reset button if safe.

Reset button is located on the side of booster heater, covered with white rub­ber cap. See 4. PART NAMES AND FUNCTIONS to nd out its position.

3.

Booster heater breaker (ECB1) tripped.

3. Check the cause and reset if safe.

4. The booster heater thermal cut-out has

tripped and cannot be reset using the manual

reset button.

4. Check resistance across the thermal cut-out, if open then connection is bro-

ken and the booster heater will have to be replaced.

Contact your Mitsubishi Electric dealer.

5. Immersion heater cut-out has been triggered. 5. Check immersion heater thermostat and press reset button located on im-

mersion heater boss, if safe. If the heater kept running with no water inside,
this may have resulted in failure, so replace it with a new one.

6.

Immersion heater breaker (ECB2) tripped.

6. Check the cause and reset if safe.

7.

Flow rate of the sanitary circuit may be reduced.

7. Check the following items

• Check for trapped air in water pump (sanitary circuit).

• Check if the speed of water pump (sanitary circuit) is set to 2.

• Check water pump (sanitary circuit) for malfunction. (Refer to section 10-6.)

• Replace plate heat exchanger (water - water) or scale trap, if there are a
blockage which blocks the sanitary circuit.

10 Temperature of DHW

tank water dropped.

When DHW operation is not running, the DHW
tank emits heat and the water temperature
decreases to a certain level. If water in the DHW
tank is reheated frequently because of a signi­cant drop in water temperature, check for the
following.

1. Water leakage in the pipes that connect to
the DHW tank

1. Take the following measures.

• Retighten the nuts holding the pipes onto the DHW tank.

• Replace seal materials.

• Replace the pipes.

2. Insulation material coming loose or off. 2. Fix insulation.

3. 3-way valve failure 3. Check plumbing/wiring to 3-way valve.

(i)

Manually override 3-way valve using the main controller. (Refer to <Manual

operation> in section 9-4.) If the valve does not still function, go to (ii) below.

(ii)

Replace 3-way valve motor. If the valve does not still function, go to (iii) be­low.

(iii) Replace 3-way valve. (Refer to 11. DISASSEMBLY PROCEDURE.)

4. Water pump (sanitary circuit) speed setting
failure

4. Water pump (sanitary circuit) MUST be set to speed 2

.

When it set to speed 1, hot water would be mixed with cold water due to

circulation.

11 Hot or warm water

from cold tap.

Heat of hot water pipe is transferred to cold water

pipe.

Insulate/re-route pipework.

12 Water leakage 1. Poorly sealed connections of water circuit

components

1. Tighten connections as required.

2. Water circuit components reaching the end of
life

2. Refer to PARTS CATALOG for expected part lifetimes and replace them as
necessary.

13 Heating system does

not reach the set
temperature.

1. Prohibit, schedule timer or holiday mode se­lected.

1. Check settings and change as appropriate.

2. Check settings and change as appropriate. 2. Check the battery power and replace if at.

3. The temperature sensor is located in a room
that has a different temperature relative to
that of the rest of the house.

3. Relocate the temperature sensor to a more suitable room.

4. Heat pump not working. 4. Check heat pump – consult outdoor unit service manual.

5. Booster heater cut-out tripped. 5. Check booster heater thermostat and press reset button if safe.

Reset button is located on the side of booster heater, covered with white rub­ber cap. (See 4. PART NAMES AND FUNCTIONS for position.)

6.

Booster heater breaker (ECB1) tripped.

6. Check the cause of the trip and reset if safe.

7. The booster heater thermal cut-out tripped

and can not be reset using the manual reset

button.

7.

Check resistance across the thermal cut-out, if open then the connection is bro-

ken and the booster heater will have to be replaced.

Contact your Mitsubishi Electric dealer.

8. Incorrectly sized heat emitter. 8. Check the heat emitter surface area is adequate

Increase size if necessary.

9. 3-way valve failure 9. Check plumbing/wiring to 3-way valve.

(i) Manually override 3-way valve using the main controller. (Refer to <Manual

operation> in 9-4). If the 3-way valve does not function, go to (ii) below.

(ii) Replace 3-way valve

motor

. If the 3-way valve coil is replaced but the

3-way valve does not function go to (iii) below.

(iii)

Replace 3-way valve. (Refer to

11. DISASSEMBLY PROCEDURE

.)

10. Battery problem (*wireless control only) 10. Check the battery power and replace if at.

11. If a mixing tank is installed, the ow rate be-

tween the mixing tank and the cylinder unit is
less than that between the mixing tank and

the local system.

11. Increase the ow rate between the mixing tank and the cylinder unit decrease

that between the mixing tank and the local system.

OCH570

55

No. Fault symptom Possible cause Explanation - Solution

14 In 2-zone tempera-

ture control, only
Zone2 does not
reach the set tem­perature.

1. When Zone1 and Zone2 are both in heating

mode, the hot water temperature in Zone2
does not exceed that in Zone1.

1. Normal action no action necessary.

2. Faulty wiring of motorized mixing valve 2. Refer to installation manual, "5.3 Wiring for 2-zone temperature control".

3. Faulty installation of motorized mixing valve 3. Check for correct installation. (Refer to the manual included with each motor-

ized mixing valve.)

4. Incorrect setting of Running time 4. Check for correct setting of Running time.

5. Motorized mixing valve failure 5. Inspect the mixing valve. (Refer to the manual included with each motorized

mixing valve.)

15

When a PUHZ-FRP
outdoor unit is con­nected, DHW or Heat-

ing operation cannot

run.

The outdoor unit is set to have operation of the
indoor unit of air conditioner take precedence over
that of the cylinder unit, and in the main control-

ler settings "Electric heater (Heating)" or "Electric
heater (DHW)" is turned off.

Turn ON Electric heater (Heating) or Electric heater (DHW) using the main con-

troller.

16 When a PUHZ-FRP

outdoor unit is con­nected and is in heat
recovery operation,
the set temperature
is not reached.

When the outdoor unit is set to have cooling

operation of the indoor unit of air conditioner take
precedence over that of the cylinder unit, the out­door unit controls the frequency of the compres-

sor according to the load of air conditioner. The
DHW and heating run according to that frequency.

Normal operation no action necessary.

If Air-to-Water system is given priority in operation, comp Hz can be regulated
depending on the load of DHW or Heating. For more details, refer to the PUHZ-

FRP installation manual.

17 After DHW operation

room temperature

rises slightly.

At the end of the DHW mode operation the 3-way
valve diverts hot water away from the DHW circuit
into space heating circuit.

This is done to prevent the cylinder unit compo-

nents from overheating.
The amount of hot water directed into the space
heating circuit varies according to the type of the
system and of the pipe run between the plate heat
exchanger and the cylinder unit.

Normal operation no action necessary.

18

The room tempera-

ture rises during DHW

operation.

3-way valve failure Check the 3-way valve.

(i) Manually override 3-way valve using the main controller. (Refer to <Manual

operation> in 9-4). If the 3-way valve does not function, go to (ii) below.

(ii) Replace 3-way valve coil. If the 3-way valve coil is replaced but the 3-way

valve does not function go to (iii) below.

(iii) Replace 3-way valve. (Refer to 11. DISASSEMBLY PROCEDURE.)

19 Water discharges

from pressure relief
valve.
(Primary circuit)

1. If continual – pressure relief valve could bite

foreign objects and the valve seat may be
damaged.

1. Turn the handle on the pressure relief valve several turns. If leakage persists,
replace the pressure relief valve with a new one.

2. If intermittent – expansion vessel charge may
have reduced/bladder perished.

2. Check pressure in expansion vessel.

Recharge to 1 bar if necessary.
If bladder perished replace expansion vessel with a new one.

20 Water discharges

from pressure relief
valve.
(Sanitary circuit)

1. If continual – eld supplied pressure reducing

valve not working.

1.

Check function of pressure reducing valve and replace if necessary.

2. If continual – pressure relief valve could bite
foreign objects and the valve seat may be
damaged.

2. Turn the handle on the pressure relief valve several turns. If leakage persists,
replace the pressure relief valve with a new one.

3. If intermittent – expansion vessel charge may
have reduced/bladder perished.

3. Check gas-side pressure in expansion vessel.

Recharge to correct precharge pressure if necessary.
If bladder perished replace expansion vessel with a new one with appropriate
pre-charge.

4. DHW tank may have subjected to backow. 4. Check the pressure in DHW tank. If pressure in DHW tank is similar to that in

the incoming mains, cold water supply that merges with incoming mains wa­ter supply could ow back to DHW tank. Investigate source of back-feed and
rectify error in pipework/tting conguration. Adjust pressure in cold supply.

21 Water discharges

from temperature
and pressure relief
valve
(EH*T20*-MHCW only)
(Sanitary circuit)

1. If continual – eld supplied pressure reducing

valve not working.

1. Check function of pressure reducing valve and replace if necessary.

2. If continual – temperature and pressure relief

valve could bite foreign objects and the valve
seat may be damaged.

2. Turn the handle on the temperature and pressure relief valve several turns.

If leakage persists, replace the temperature and pressure relief valve with a
new one.

3. If intermittent – expansion vessel charge may
have reduced/bladder perished.

3. Check gas-side pressure in expansion vessel.

Recharge to correct precharge pressure if necessary.
If bladder perished replace expansion vessel with a new one with appropriate
pre-charge.

4. DHW tank may have subjected to backow. 4. Check pressure in DHW tank. If pressure in DHW tank is similar to that in the

incoming mains, cold water supply that merges with incoming mains water
supply could flow back to DHW tank. Investigate source of back-feed and
rectify error in pipework/tting conguration. Adjust pressure in cold supply.

5. Unit has overheated – thermal controls have
failed.

5. Switch off power to the heat pump and immersion heaters.

Leave water running.
Wait until discharge stops. Isolate water supply and replace if faulty.

OCH570

56

No. Fault symptom Possible cause Explanation - Solution

22

Water discharges from
expansion relief valve

- part of Inlet Control
Group
(EH*T20*-MHCW only)
(sanitary circuit)

1. If continual – eld supplied pressure

reducing valve not working.

1. Check function of pressure reducing valve and replace if necessary.

2. If continual – expansion relief valve may be

damaged.

2. Turn the handle on the expansion relief valve to check for foreign objects
inside. If the problem is not still solved, replace the expansion relief valve
with a new one.

3. If intermittent – expansion vessel charge
may have reduced/bladder perished.

3. Check gas-side pressure in expansion vessel.

Recharge to correct precharge pressure if necessary.
If bladder perished replace expansion vessel with a new one with
appropriate precharge.

4. DHW tank may have subjected to backow. 4. Check pressure in DHW tank. If pressure in DHW tank is similar to that in

the incoming mains, cold water supply that merges with incoming mains
water supply could ow back to DHW tank. Investigate source of back­feed and rectify error in pipework/tting conguration. Adjust pressure in

cold supply.

5. Unit has overheated – thermal controls have
failed.

5. Switch off power to the heat pump and immersion heaters. Leave water

running. Wait until discharge stops. Isolate water supply and replace if

faulty.

23

Noisy water circulation

pump

Air in water circulation pump. Use manual and automatic air vents to remove air from system.

Top up water if necessary to achieve 1 bar on primary circuit.

24 Noise during hot water

draw off typically
worse in the morning.

1. Loose airing cupboard pipework. 1. Install extra pipe fastening clips.

2. Heaters switching on/off. 2. Normal operation no action necessary.

25 Mechanical noise

heard coming from the

cylinder unit.

1. Heaters switching on/off. Normal operation no action necessary.

2. 3-way valve changing position between

DHW and heating mode.

26

Water circulation pump
runs for a short time

unexpectedly.

Water circulation pump jam prevention mechanism

(routine) to inhibit the build-up of scale.

Normal operation no action necessary.

27 Milky/Cloudy water

(Sanitary circuit)

Oxygenated water Water from any pressurised system will release oxygen bubbles when water is

running. The bubbles will settle out.

28 Heating mode has

been on standby for

a long time (does

not start operation
smoothly.)

The time of “Delay” set in “Economy settings

for pump” is too short. (Go to “Service menu”

→ “Auxiliary settings” → “Economy settings for

pump”).

Increase the time of “Delay” in “Economy settings for pump” .

29 The cylinder unit

that was running in
the heating mode
before power failure
is running in the DHW
mode after power

recovery.

The cylinder unit is designed to run in an operation
mode with a higher priority (i.e. DHW mode in this
case) at power recovery.

• Normal operation.

• After the DHW max. operation time has elapsed or the DHW max. temperature
has been reached, the DHW mode switches to the other mode (ex. Heating

mode).

30

The energy monitor val­ue seems not correct.

1. Incorrect setting of the energy monitor 1. Check the setting by following the procedure below.
(1) Check if the DIP switch is set as the table below.
Consumed electric energy

SW3-4

Electric energy meter

(Local supply)
OFF Without
ON With

(2) In the case external electric energy meter and/or heat meter is not used,

check if the setting for electric heater and water pump(s) input is correct by
referring to <Energy monitor setting> in section 9-4.

(3) In the case external electric energy meter and/or heat meter is used, check

if the unit of output pulse on external meter matches with the one set at the
main controller by referring to <Energy monitor setting> in section 9-4.

2. Non-connectable type of external meter (local

supply) is connected.

2. Check if the external meter (local supply) is connectable type by referring to
<Energy monitor setting>" in section 9-4.

3. External meter (local supply) failure 3. Check if signal is sent to IN8 to IN10 properly. (Refer to section 6. WIRING

DIAGRAM)

Replace the external heat meter if defective.

4. FTC board failure 4. Check the FTC control board.

• Check for faulty wiring.

• If no problem found with the wiring, the FTC control board is faulty. Replace

the board.

Delivered heat energy

SW3-8

Heat meter

(Local supply)
OFF Without
ON With

OCH570

10-6. Checking component parts' function

Part Name Check Points

Water circulation pump (primary circuit)

Water circulation pump (sanitary circuit) Measure the resistance between the terminals with a tester.

(Winding temperate 20°C)

Terminal Normal (speed 2) Abnormal

L-N 211 Ω Open or Short

DHW circulation pump MUST be set to speed 2.

Immersion heater Measure the resistance between the terminals with a tester.

(Winding temperate 20°C)

Terminal Normal Abnormal

A-B 19.2 Ω Open or Short

To reset the immersion heater use a pin or similar to press the reset button lo­cated on the top of the immersion boss.

See diagram on the left.

L

Signal cable

3

3

Power cable

BROWN

PWM input signal

Feedback signal

Signal ref.

BLUE

BROWN

GREEN/
YELLOW

BLUE

BLACK

M

1~

N

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

0.0 5.0 10.0 15.0 20 .0 25 .0 30 .0 35 .0 40 .0

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

0.0 5.0 10.0 15.0 20 .0 25 .0 30 .0 35 .0 40 .0

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

0.0 5.0 10.0 15.0 20 .0 25 .0 30 .0 35 .0 40 .0

L N

M

1~

57

<Water circulation pump (primary circuit) characteristics>

<Recommendedwaterowraterange>

Outdoor heat pump unit Waterowraterange[L/min]

Packaged model PUHZ-W50 7.1-14.3

PUHZ-W85 10.0-25.8
PUHZ-W112 14.4-27.7
PUHZ-HW112 14.4-27.7
PUHZ-HW140 17.9-27.7

Split model SUHZ-SW45 7.1-12.9

PUHZ-SW40 7.1-11.8
PUHZ-SW50 7.1-17.2
PUHZ-FRP71 11.5-22.9
PUHZ-SW75 10.2-22.9
PUHZ-SW100 14.4-27.7
PUHZ-SW120 20.1-27.7
PUHZ-SHW80 10.2-22.9
PUHZ-SHW112 14.4-27.7
PUHZ-SHW140 17.9-27.7

External static pressure [kPa]

Flow rate [L/min]

Speed 5 (Default setting)

Speed 4

Speed 3

Speed 2

Speed 1

External static pressure [kPa]

Flow rate [L/min]

External static pressure [kPa]

Flow rate [L/min]

Speed 5 (Default setting)

Speed 4

Speed 3

Speed 2

Speed 1

Speed 5 (Default setting)

Speed 4

Speed 3

Speed 2

Speed 1

EHST20C series

EHST20D series

EHPT20X series

OCH570

Part Name Check Points

Flow sensor

Booster heater Measure the resistance between the terminals with a tester.

Thermostat (90 °C) and thermal cut out (121 °C)

90 °C
Manual reset
water
thermostat

121 °C
Thermal
cut-out

AWG18

AWG18

9

10

Terminal Normal Abnormal

9-10 110(±35)mΩ Open or Short

2kW heater (230V, 1 phase)

1

2

2kW

AWG15 FEP

WHITE

AWG15 FEP

WHITE

Terminal Normal Abnormal

1-2 26.5(+3/-1.3)Ω Open or Short

2 + 4kW heater (230V, 1 phase)

1

2

2kW

AWG15 FEP

WHITE

AWG15 FEP

WHITE

3

4

2kW

AWG13 FEP

BLUE

AWG13 FEP

BLUE

2kW

Terminal Normal Abnormal

1-2 26.5(+3/-1.3)Ω Open or Short
3-4 13.3(+1.5/-0.6)Ω Open or Short

3 + 6kW heater (400V, 3 phase)

5 6

AWG13 FEP

BLUE

AWG13 FEP

BLUE

AWG15 FEP

WHITE

2kW

4

AWG13 FEP

BLUE

2kW 2kW

2 3

1kW

1

1kW 1kW

AWG15 FEP

WHITE

AWG15 FEP

WHITE

Terminal Normal Abnormal

1-2=2-3=1-3 105.8(+11.8/-5)Ω Open or Short
4-5=5-6=4-6 52.9(+5.8/-2.5)Ω Open or Short

3 + 6kW heater (230V, 3 phase)

Terminal Normal Abnormal

1-2=2-3=3-1

35.3(+3.9/-1.8)Ω Open or Short

4-5=5-6=6-4 17.6(+1.9/-0.9)Ω Open or Short

Earth leakage circuit breaker for heater If a short circuit occurs on the booster heater, immersion heater, or each power

line, a short-circuit breaker will trip and power source will be blocked.
Eliminate the causes of short circuit and then turn on the breaker again.

Relay for heater

R S T A1 A2

U V W

When the applied voltage is not 230V AC across the terminals A1-A2, check the

terminals R-U, S-V, and T-W are open.

When the applied voltage is 230V AC across the terminals A1-A2, check the

terminals R-U, S-V, and T-W are short.

5 6

AWG13 FEP

BLUE

AWG13 FEP

BLUE

AWG15 FEP

WHITE

4

AWG13 FEP

BLUE

2kW 2kW

2 31

1kW 1kW

AWG15 FEP

WHITE

AWG15 FEP

WHITE

2kW

1kW

Yellow

White

Green

Brown

Flow signal V

5V DC

CN1A

1

4

Flow signal

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

0.0
0 20 40 60 80 100

Flow [l/min]

Flow output signal[V]

0.35V

58

OCH570

Part Name Check Points

3-way valve

AB

AB

A

A

B

A

B

Motor

Valve

Indicator (red)

Release button

B

<DHW> <Heating>

AB

(1) Check the movement of the red indicator. The red indicator normally points

to A in DHW mode and to B in Heating mode as shown to the left.

(2) If each indicator position is correct but the 3-way valve does not work prop-

erly, the motor may not t onto the valve securely, so remove the motor by
pressing the release button, and reinstall it.

Thermistors Disconnect the connector then measure the resistance with a tester.

(At ambient temperatures of 10 - 30°C.)

Thermistor Normal Abnormal

TH1

4.3 - 9.5 kΩ Open or short

TH2
THW1
THW2
THW5
THW6
THW7
THW8
THW9
THWB1

40 - 100 kΩ Open or short

THWB2

• Boiler flow water temperature thermistor (THWB1)

• Boiler return water temperature thermistor (THWB2)

0

10

20

30

40

50

-20 -10 0 10 20 30 40 50

Temperature (:)

Resistance (k")

<Thermistor Characteristics Charts>

• Room temperature thermistor (TH1)

• Liquid refrigerant temperature thermistor (TH2)

• Flow water temperature thermistor (THW1)

• Return water temperature thermistor (THW2)

• DHW tank temperature thermistor (THW5)

• Zone 1 ow water temperature thermistor (THW6)

• Zone 1 return water temperature thermistor (THW7)

• Zone 2 ow water temperature thermistor (THW8)

• Zone 2 return water temperature thermistor (THW9)

0°C 15kΩ
10°C 9.6kΩ
20°C 6.3kΩ
25°C 5.2kΩ
30°C 4.3kΩ
40°C 3.0kΩ

Thermistor R0 = 15kΩ ± 3%
B constant = 3480 ± 2%

Rt = 15exp {3480 (

273+t

–

273

)}

1

1

0

10 0

20 0

30 0

40 0

50 0

60 0

70 0

80 0

90 0

10 0 0

-3 0 -2 0 -10 0 1 0 20 30 40 50 60 70 80

Temperature (°C)

Resistance (kΩ)

0°C 162.8kΩ
10°C 97.4kΩ
20°C 60.3kΩ
25°C 48.1kΩ
30°C 38.6kΩ
40°C 25.4kΩ
50°C 17.1kΩ
60°C 11.9kΩ
70°C 8.4kΩ
80°C 6.0kΩ

Thermistor R100 = 3.3kΩ ± 2%

B constant = 3970 ± 1%

Rt = 3.3exp {3970 (

273+t

–

273

)}

1

1

59

OCH570

10-7. Test point diagram

FTC (Controller board)

60

CN3C
Transmission
(Indoor/Outdoor)
(0 - 24V DC)

LED3
Transmission
(Indoor/Outdoor)

CNP1/OUT1 (TBO.1 1-2)
Water circulation pump1
(230V AC)

F2

6.3A/250V

CN01

Power supply

(230V AC)

F1
10A/250V

CNPWM
Water circulation
pump 1
(2 - 3: 5V DC)

OUT12 (TBO.3 5-6)

Signal output (Defrost) (230V AC)

OUT8 (TBO.4 5-6)

Signal output (Cooling)

(230V AC)

CNIH/OUT9 (TBO.4 3-4)

Signal output for immersion

heater

(230V AC)

CNBHT
Thermostat input for
booster heater

IN7
(TBI.1 1-2)

Flow switch 3 input

CN22/RC(TBI.2 1-2)
Main controller
(10.4 - 13.7 V DC)

CNRF
Transmission (Indoor/
Wireless receiver)
(1-2: 11.5 - 13.2 V DC)

LED1

Power supply (FTC)

CN108
SD card

LED4

Reading or writing

data to SD card

LED2

Power supply

(Main controller)

THW9
(TBI.2 9-10)
Thermistor
(Zone2 return

water temp. )

THW7
(TBI.2 5-6)
Thermistor
(Zone1 return

water temp. )

THW6
(TBI.2 3-4)
Thermistor

(Zone1 flow
water temp. )

THWB1
(TBI.2 11-12)
Thermistor

(Boiler flow
water temp.)

THW8
(TBI.2 7-8)
Thermistor

(Zone2 flow
water temp. )

IN6
(TBI.1 3-4)
Room thermostat 2
input

IN5
(TBI.1 5-6)
Outdoor ther­mostat input

IN4
(TBI.1 7-8)
Demand
control input

IN3
(TBI.1 9-10)

Flow switch

2 input

IN1
(TBI.1 13-14)
Room thermo­stat input

CNBC

Signal output for booster heater

(230V AC)

OUT11 (TBO.3 3-4)

Signal output (Error) (230V AC)

OUT5 (TBO.2 1-3)

Mixing valve (Local supply)
(1-2[Close]: 230VAC)
(2-3[Open]: 230VAC)

CNP4/OUT14
Water circulation pump4
(230V AC)

OUT3 (TBO.1 5-6)
Water circulation pump3
(Local supply) (230V AC)

OUT2 (TBO.1 3-4)
Water circulation pump2
(Local supply) (230V AC)

CNBH

Signal output for booster heater

(1-3: heater1 230V AC)
(5-7: heater2 230V AC)

OUT13 (TBO.4 1-2)

2-way valve2 (230V AC)

CNV1/OUT4 (TBO.2 4-6)

3-way valve

(4-5: 230V AC)

OUT10 (TBO.3 1-2)

Signal output (Boiler)
(non-voltage contact)

OUT15 (TBO.3 7-8)

Signal output (Comp on)

(230V AC)

IN2
(TBI.1 11-12)

Flow switch 1

input

IN8
(TBI.3 1-2)

Power meter 1

input

CN20
Thermistor
(Room temp.)

CN21
Thermistor
(Ref. liquid temp.)

CNW12
Thermistor

(1-2: Flow water temp.)
(3-4: Return water temp.)

THWB2
(TBI.2 13-14)
Thermistor
(Bolier return

water temp. )

IN9
(TBI.3 3-4)

Power meter

2 input

CN1A

Flow sensor

input

CNW5
Thermistor
(DHW tank

water temp.)

IN10
(TBI.3 5-6)
Heat meter
input

CN105
Transmission (Indoor/
WiFi adaptor)
(1-2: 11.5 - 13.2 V DC)

OCH570

PHOTOS & ILLUSTRATION

61

DISASSEMBLY PROCEDURE

1. How to remove the front panel

(1) Remove the 2 screws at the bottom of the cylinder unit.

(Photo 1-1)

(2) Slightly lift and pull out the front panel from the cylinder

unit. (Photo 1-1)

(3) Disconnect the relay connector connecting from the main

remote controller. (Photo 1-2)

Photo 1-1

Photo 1-2

2. How to remove the main remote controller

(1) Remove the front panel (Refer to Procedure 1).
(2) Turn the front panel over and remove the main remote

controller holder by removing the 5 claws. (Photos 2-1

and 2-2)

(3) Slide the main remote controller support upward, then

remove it together with the main remote controller.

(Photos 2-2)

(4) Separate the main remote controller from the main

remote controller support. (Photos 2-1 and 2-3)

Photo 2-1

Front panel fixing screws

Front panel

Main remote controller

Front panel

Connector

Main remote
controller support

Photo 2-2 Photo 2-3

11

DISASSEMBLY PROCEDURE

Check individual illustrations and positions of the parts by referring to the parts catalog.
Some lead wires and pipes are bundled with bands. Cut the bands to undo the fastened pipes and lead wires if necessary. When bundling the
lead wires and pipes again, use new commercially available bands.
When removing the parts associated with water pipe work, drain the cylinder unit as necessary. Refer to "Draining the cylinder unit" on page 24.
When draining the cylinder unit, keep water from splashing on the internal parts (mainly electric parts and insulations).

<Preparation for the repair service>

● Prepare the proper tools.

● Prepare the proper protectors.

● Provide adequate ventilation.

● After stopping the operation of the cylinder and outdoor unit, turn off the power-supply breaker and remove the power plug.

● Discharge the condenser before the work involving the electric parts.

● Allow parts to cool.

● Do not expose the electric parts to water.

● When replacing or servicing water circuit parts, drain system first.

Main remote controller

Main remote
controller

Claws

Claw

Main remote
controller holder

OCH570

PHOTOS

62

DISASSEMBLY PROCEDURE

Photo 3-2

Photo 3-1

3. How to remove the electrical parts

(Step (1) is applied to all the following parts.)

(1) Remove the front panel (Refer to Procedure 1).

<Earth leakage circuit breaker> (Photo 3-1)

(2) Disconnect all the lead wires from the earth leakage cir-

cuit breaker.

(3)

Remove the 2 screws on the earth leakage circuit breaker.

Note:

To avoid dropping of the breaker, hold the breaker by
hand when removing the last screws.

<Contactor> (Photo 3-1)

(2) Disconnect all the lead wires from the contactors.
(3) Remove the 2 screws on each contactor.

Note:

To avoid dropping of the contactors, hold the contac­tors by hand when removing the last screws.
To prevent an electrical shock, wait until all the LED
lamps on the FTC control board are turned off.

<Terminal block> (Photo 3-1)

(2) Disconnect all the lead wires from the terminal block. (To

disconnect the S1, S2 and S3 lead wires, disengage the
locks by pressing on the claws.)

(3) Remove the screw on the terminal block.

Note:

To avoid dropping of the terminal block, hold the
terminal block by hand when removing the screw.

<Controller board> (Photo 3-2)

(2) Disconnect all the lead wires from the controller board.

(3) Remove the controller board from the 4 board supports.

* The photos shown are of the EHST20C-VM6C model

with optional immersion heater.

Terminal block (TB1)

Earth leakage circuit

breakers (ECB1, ECB2)

Contactors

Control box

Controller
board

Controller
board

Screw

Board supports

Board supports

OCH570

PHOTOS

63

Bracket (R)

DISASSEMBLY PROCEDURE

Photo 4-1

Photo 4-3

4. How to remove the control box

(1) Remove the front panel (Refer to Procedure 1).

(2) Disconnect only the lead wires in the control box that

connect to the components in the cylinder unit.

Photo 4-2 shows the control box before the related lead
wires are disconnected.

(3) Remove the 3 screws on the bracket (L and R) and

disengage the tab on the control box bracket from the

front frame (L). (Photo 4-1)

(4) Disengage the 2 tabs on the control box bracket (R) from

the front frame (R). (Photo 4-1)

(5) Slightly lift and pull out the control box from the cylinder

unit while tilting the control box backward.

<When swinging the control box to the front>

(2

)

Remove the 3 screws on the bracket (L and R). (Photo 4-1)

(3) Disengage the tab on the control box bracket (L) from

the front frame (L) and pull the control box by lifting the
left-hand side to swing the control box. (Photo 4-3)

Note: Disconnect the field wiring as necessary.

* The photos shown are of the EHST20C-YM9C model.

Control box

Front
frame (R)

Swing

Bracket (L)

Cable
clamps

Cable
strap

Photo 4-2

Screw

Front
frame (L)

* The photos shown are of the EHST20C-VM6C model

with optional immersion heater.

Screw

Control

box

Tab

Tab

Tab

Fastener

CN1A connector

CNV1
connector

CNPWM connector

CNP4
connector

CNP1
connector

Earth cable of

water pump

(primary circuit)

Earth cable of

water pump

(sanitary circuit)

Cable
strap

Screw

OCH570

PHOTOS

64

5. How to remove water pump (primary circuit)/pump valve/
strainer valve

<Water pump>

(1) Remove the front panel (Refer to Procedure 1).
(2) Disconnect the CNP1 connector, the earth cable and the

CNPWM connector in the control box. (Photo 4-2)

(3) Release the water pump lead wire from the 2 cable

clamps, the fastener and the cable strap in the control

box, and the cable strap, the coated clamp and the 3
bands below the control box. (Photos 4-1 and 10-1)

(4) Close (OFF) the pump valve and the strainer valve

(Photo 5-1)

•

When either of the pump valve handle or the strainer

valve handle is stiff, use a tool to grip the handle and

turn it carefully.

• When opening or closing the pump valve and the
strainer valve, ensure to do so fully, not halfway.

(5) Remove the water pump by removing the two G1" nuts

using the two spanners: one to hold the G1" nut and the
other to turn the other side of G1" nut. Remove the water
pump by sliding it horizontally. (Photo 5-1).

• When reinstalling the G1" nuts, use new G1" gaskets.

(Photos 5-2 and 5-3)

• Set the water pump in the way that the die stamped
arrow facing down, and the terminal box facing to the

left.

<Pump valve>

(6) Remove the 2 screws on the pump valve stay. (Photo

5-1)

(7)

Remove the pump valve by detaching the quick connection.

• When reinstalling the quick connection, use new O-ring.

•

Refer to Procedure 23 for how to attach and detach the

quick connection.

(8)

Remove the pump valve stay by removing the 2 screws,

and remove the drain cock (primary circuit). (Photo 5-4)

• Reuse the removed pump valve stay and the pump
valve stay fixing screws.

• When reinstalling the drain cock (primary circuit), use a
new one.

Note: Skip Steps (2) and (3) above when replacing the

pump valve only.

Photo 5-1

Photo 5-2

Photo 5-3

DISASSEMBLY PROCEDURE

Quick connection
O-ring

Strainer
valve

Water pump
(primary circuit)

Nut (G1")
Gasket (G1")

Terminal

box

Quick

connection

Strainer valve
handle

Pump valve

Pump valve
handle

Nut (G1")
Gasket (G1")

Gasket

(G1")

Gasket (G1")

O-ring

Strainer
valve stay

Screws

Screws

Pump valve stay

Continue to the next page.

Photo 5-4

Screws

Flow direction

Pump valve stay

Drain cock
(primary circuit)

OCH570

PHOTOS

65

Photo 6-1

6. How to remove the 3-WAY VALVE / 3-WAY VALVE MOTOR

(1) Remove the front panel (Refer to Procedure 1).
(2) Disconnect the CNV1 connector on the controller board.

(Photo 4-2)

(3) Release the 3-way valve motor lead wire from the 2

cable clamps, the fastener and the cable strap in the

control box, and the cable strap, the coated clamp and
the band below the control box. (Photos 4-1 and 10-1)

(4) Remove the 3-way valve motor from the 3-way valve by

pressing the button on the 3-way valve motor (viewed

from the front of the cylinder unit). (Photos 6-1 and 6-2)

• Press the button also when reinstalling the 3-way valve

motor.

(5) Remove the 3-way valve by removing the 3 G1" nuts in

the order of the bottom, middle and top using two
spanners: one to hold the 3-way valve and the other to

turn each nut. (Photos 6-1 and 6-2)

• When reinstalling the G1" nuts, use new G1" gaskets. A
and B shown represent the bottom and the top
directions of the 3-way valve, respectively.

Note:

Before replacing the motor, be sure to power off the

cylinder unit.
Failure to do so may cause electric shock or cause the

3-way valve to malfunction.

Photo 6-2

DISASSEMBLY PROCEDURE

3-way

valve
motor

3-way valve motor Button

A

B

Nut (G1")

Nut (G1")

Gasket(G1")

Gasket(G1")

Place to hold the 3-way valve
with a spanner

3-way valve

3-way valve

Gasket(G1")

Nut (G1")

<Strainer valve>

(6)

Remove the 2 screws on the strainer valve stay. (Photo 5-1)

(7) Remove the strainer valve by detaching the quick con-

nection.

• When reinstalling the quick connection, use a new
O-ring.

• Refer to Procedure 23 for how to attach and detach the

quick connection.

(8) Remove the strainer valve stay by removing the 2

screws. (Photo 5-5)

• Reuse the removed strainer valve stay and the strainer
valve stay fixing screws.

Note: Skip steps (2) and (3) when replacing the strainer

valve only.

<Strainer cover (debris recovery)>

(5) Remove the cover using two spanners: one to hold the

strainer valve and the other to turn the cover. (Photo 5-5)

•

Be sure to reattach the mesh after washing it. (Photo 5-6)

• When reinstalling the cover, use a new packing. (Photo

5-6)

Note: Skip Steps (2) and (3) above when washing the stain-

er mesh only.

Photo 5-6

From the previous page.

Strainer mesh

PackingCover

Button

Photo 5-5

Strainer valve stay

Screws

Cover Strainer mesh (inside)

OCH570

PHOTOS

DISASSEMBLY PROCEDURE

66

7. How to remove the flow sensor

(1) Remove the front panel (Refer to Procedure 1).
(2) Disconnect the CN1A connector on the controller board.

(Photo 4-2)

(3) Release the flow sensor lead wire from the cable clamp,

the fastener and the cable strap in the control box, and
the cable strap, the coated clamp and the 3 bands below
the control box. (Photos 4-1 and 10-1)

(4) Close (OFF) the strainer valve. (Photo 5-1)

•

When the strainer valve handle is stiff, use a tool to grip

the handle and turn it carefully.

•

When opening or closing the strainer valve, ensure to do
so fully, not halfway.

(5) Loosen the nuts using two spanners, and remove the

flow sensor; one to hold the flow sensor and the other to

turn the nut.(Photos 7-1 and 7-2)

• When reinstalling the flow sensor, use a new O-rings.
(Photo 7-2)

Note: Set the flow sensor in the direction of the arrow print-

ed on the flow sensor, and in the way that the sensor

part faces to the left. (Photo 7-1)

Photo 7-1

Photo 7-2

Sensor part

O-ring

Lead wire

Nut (G1")

O-ring

Place to hold

the flow sen­sor with a

spanner

Flow direction

Nut (G1")

O-ring

Flow sensor

OCH570

DISASSEMBLY PROCEDURE

PHOTOS

67

8. How to remove the booster heater

(1) Remove the front panel (Refer to Procedure 1).
(2) Disconnect the CNBHT connector on the controller

board, and the booster heater lead wires wired to the
BHC1 (Lead wire No.1, No.2 and No.3) and BHC2
(Lead wire No.4, No.5 and No.6) contactors respectively
and release the lead wires from the fastener, the cable

clamp, the 2 cable straps, the coated clamp and the 3
bands. (Photos 8-1 and 10-1)

Note: Do not mix up the lead wire numbers when

re-connecting the lead wires to the contactors as
the lead wire numbers are different dependent on

the models.

Model Lead wire No. Contactor
EHST20C-VM6C
EHST20C-VM6EC
EHPT20X-VM6C

No.1 BHC1-U

No.2 BHC1-V

No.3 BHC2-U

No.4 BHC2-V

EHST20C-YM9C
EHST20C-TM9C
EHST20C-YM9EC
EHPT20X-YM9C
EHPT20X-TM9C

No.1 BHC1-U

No.2 BHC1-V

No.3 BHC1-W

No.4 BHC2-U

No.5 BHC2-V

No.6 BHC2-W

EHST20C-VM2C
EHST20C-VM2EC
EHST20D-VM2C
EHPT20X-VM2C

No.1 BHC1-U

No.2 BHC1-V

Refer to 6. WIRING DIAGRAM

* The photos shown are of the EHST20C-VM6C model.

Screw

Flare nut

Photo 8-1

Photo 8-2

Pipe (W.C. - B.H.)

Terminal
block (TB1)

Earth leakage circuit

breaker (ECB1)

Contactors

Control boxController

board

CNBHT
connector

Gasket

(G1")

Heater stay

P-HEX

Booster heater

Screw

Quick connection of

inlet of booster heater

Quick connection

of outlet of P-HEX

Band and rubber

Pump valve

Nut

(G1")

Gasket

(G1")

Nut

(G1")

Continue to the next page.

No.1

No.2

No.3

No.4

No.5

No.6

Cable
clamp

Cable
strap

Front frame (L)

Screws

Screw

O-ring

O-ring

Pipe (B.H.-D.V.)

Band

DIV frame

Screws

Cushion

Pipe (to F.S.)

Quick connection

(upper F.S.)

OCH570

DISASSEMBLY PROCEDURE

PHOTOS

68

Photo 8-3

Photo 8-4

Quick connec­tion of inlet of
booster heater

Quick connec­tion of outlet of
P-HEX

From the previous page.

(3) Remove the DIV frame by removing the 2 screws on it, and

remove the cushion by cutting the band. Then remove the
rubber by cutting the band. (Photo 8-2)

(4) Close (OFF) the pump valve. (Photo 8-2)

•

When the pump valve handle is stiff, use a tool to grip the

handle and turn it carefully.

•

When opening or closing the pump valve, ensure to do so
fully, not halfway.

(5) Detach the 2 quick connections (Inlet of booster heater and

outlet of P-HEX) (Photos 8-2 and 8-3)

•

When reinstalling the quick connections, use new O-rings.

•

Refer to Procedure 23 for how to attach and detach the

quick connection.

(6) Remove the pipe (W.C. - B.H.) by carefully pulling it to the

right. (Photo 8-2)

(7) Loosen the two G1" nuts and remove the pipe (B.H. - D.V.)

(Photo 8-3)

•

When reinstalling the G1" nuts, use new G1" gaskets.

(8) Detach the quick connection (upper F.S.) to make the con-

nection part of pipe (to F.S.) free. (Photo 8-2)

•

When reinstalling the quick connections, use a new O-ring.

•

Refer to Procedure 23 for how to attach and detach the

quick connection.

(9) Hold the top of the booster heater using a pipe wrench and

turn the flare nut using a spanner. (Photo 8-2)

(10) Remove the 2 screws that hold the heater stay onto the

front frame (L). Lift the booster heater slightly and remove
the booster heater with the heater stay from the front

frame (L). (Photos 8-2 and 8-4)

(11) Remove the 3 screws that hold the heater stay onto the

booster heater, and remove the heater stay from the
booster heater. (Photo 8-2)

O-ringBooster heater

O-ring

P-HEX

Booster
heater

Front frame (L)

OCH570

DISASSEMBLY PROCEDURE

PHOTOS

69

9. How to remove the thermostat/immersion heater

<Thermostat>

(1) Remove the front panel (Refer to Procedure 1).

(2) Peel off the water-proof tapes on the plastic head of the

thermostat in order to reveal the thermostat terminals,
and disconnect the lead wires from the terminals.
(Photos 9-1 and 9-2)

• Use new commercially available water-proof tapes to
cover the terminals again.

(3) Pull out the thermostat.

<Immersion heater>

(4) Remove the tab cover and remove the back nut (G1-

3/4") using the tool included with the immersion heater.

(Photo 9-3)

(5) Pull out the immersion heater.

• When reinstalling the immersion heater, use a new
G1-3/4" gasket.

Note:

When replacing the immersion heater only, skip Step (2).
After reinstalling the back nut with the tab cover onto the
tank, insert the immersion heater straight into the tank
through the back nut in order to provide adequate sealing.
Failure to do so may cause water leakage.
Always check for water leakage after installation.

Water-proof tapes

Photo 9-2

Photo 9-3

Tool (*1)

Back nut

(G1-3/4")

(*1) When the model is the cylinder unit including immersion heater,

the tool is included with the unit. The tool is also included with

the immersion heater of optional parts.

Photo 9-1

Thermostat/
Immersion heater

Lead wires

OCH570

DISASSEMBLY PROCEDURE

PHOTOS

70

Photo 10-1

10. How to remove the plate heat exchanger (P-HEX)
(Refrigerant - Water)

<EHST20C model>

(1) Pump down the refrigerant circuit and close the stop

valve at the outdoor unit side.

(Refer to 12. SUPPLEMENTARY INFORMATION.)

(2) Remove the front panel (Refer to Procedure 1).

(3) Remove the control box (Refer to Procedure 4).

(4)

Remove the DIV frame by cutting the band and removing

2 screws on it. (Photo 10-1)
(5) Cut the bands bundling the pipes. (Photos 10-1 and 10-2)
(6) Remove the 2 flare nuts on the refrigerant piping on top

of the

cylinder unit. (Photo 10-3)

Photo 10-2

Photo 10-3

DIV frame

Screw

Screw

Screws

Band

Bands

Top panel

Flare nuts

P-HEX

Band

Continue to the next page.

Screws

Band

Coated
clamp

Cable
strap

Bands

OCH570

DISASSEMBLY PROCEDURE

PHOTOS

71

Continue to the next page.

Photo 10-4

Refrigerant pipes

P-HEX

From the previous page.

10. How to remove the plate heat exchanger (P-HEX)
(Refrigerant - Water)

(7) Remove the thermistor (TH2) from the thermistor pocket

(Refer to Procedure 20).

(8) Remove the manometer with the manometer cover

(Refer to Procedure 11).

(9) Loosen the flare nuts for Air vent (automatic) and

pressure relief valve (3 bar), and remove the Air vent

(automatic) and pressure relief valve (3 bar) together
with the flare joints. (Refer to Procedure 11)

(10) Loosen and remove the flare nut which connects the

expansion vessel. (Photo 12-1)

(11) Loosen and remove the flare nut on booster heater,

then remove the pipe. (over B.H.) (Photo 10-4)

(12) Remove the strainer valve, the water pump and the

pump valve (Refer to Procedure 5).

(13) Remove the nut (G1") on the B side of 3-way valve to

make the connection part free. (Photo 6-1)

• When reinstalling the nuts, use a new G1" gasket.

(14) Remove the booster heater (Refer to Procedure 8).

(15) Remove the water coil cover by removing the screw 1

to 5. Remove the W.C. top cover by removing the screw
6 and 7. Remove the pump stay by removing the screw

8 to 11. (Photo 10-5)

• Reuse these 3 plates and fixing screws.

(16)

Pull out the P-HEX. (Photos 10-6 and 10-7)

Photo 10-5

Photo 10-6

Photo 10-7

Expansion vessel

Pipe (over B.H.)

P-HEX

Screw 7Screw 6

Screw 3

Screw 5

W.C. top cover

P-HEX

Screw 2

Screw 1

Water coil
cover

Screw 4

Screw 8

Screw 9

Pump
stay

Screw 10

Screw 11

OCH570

DISASSEMBLY PROCEDURE

PHOTOS

72

Photo 10-8

10. How to remove the plate heat exchanger (P-HEX)
<EHST20D model>

(15) Remove the pump stay by removing the 3 screws on it.

(Photo 10-8)

(16) Remove the 3 screws on the front frame (L), and 1

screw on the bottom.

(Photos 10-8 and 10-9)

(17) Loosen the hooks on the plate to pull out the P-HEX with

plates from the cylinder unit by lifting them together.

(Photos 10-9 and 10-10)

(18) Remove the pipe band by removing 2 screws on it, and

remove the water coil cover by removing the 2 screws on

it. (Photo 10-10)

• Reuse the pipe band, the water coil cover and the
removed 4 fixing screws.

(19) Detach the 2 quick connections, then take out the

P-HEX.

(Photo 10-10)

•

When reinstalling the quick connections use new O-rings.

•

Refer to Procedure 23 for how to attach and detach the

quick connection.

Photo 10-9

Photo 10-10

Screws

(on the bottom)

Screws

P-HEX (inside)

Screws

Pump stay

Front
frame (L)

Hook

P-HEX (inside)

Water coil cover

Screws

Quick connectionsO-rings

Screws Pipe band

From the previous page.

OCH570

DISASSEMBLY PROCEDURE

PHOTOS

73

Photo 11-1

11. How to remove the

pressure relief valve / manometer / air

vent (automatic)

(1) Remove the front panel (Refer to Procedure 1).
(2)

Swing the control box to the front (Refer to Procedure 4).

<Manometer>

(3) Remove the G1/4" nut from the pressure relief valve

using two spanners: one to hold the joint (G1/4") and the

other to turn the manometer connection. (Photo 11-1)

• When reinstalling the G1/4" nut, use a new G1/4"
gasket. (Photo 11-1)

(4)

Remove the 2 screws and remove the manometer cover
with the manometer from the front frame (L) by sliding it
upward. (Photos 11-1 and 11-2)

(5) Remove the manometer from the manometer cover while

pressing on the 2 claws. (Photo 11-3)

• When reinstalling the manometer assembly on the unit,
beware not to put strain on the root of the capillary tube

as the capillary tube is easy to break at the root. (Photo
11-4)

Photo 11-2

Photo 11-3

Manometer

Manometer
cover

Screws

Photo 11-4

Manometer
connection (G1/4")

Joint (G1/4")

Gasket
(G1/4")

Manometer

Manometer
cover

Front frame (L)

Manometer

Manometer
cover

Claws

Manometer

Manometer
cover

Root

Capillary tube

Continue to the next page.

OCH570

DISASSEMBLY PROCEDURE

PHOTOS

74

11. How to remove the

pressure relief valve / manometer / air

vent (automatic)

<

Pressure relief valve (3 bar)>

(3) Remove the field piping from the pressure relief valve (3

bar). (Photo 11-5)

(4) Remove the pressure relief valve (3 bar) with the flare

joint using two spanners: one to hold the flare joint and

the other to turn the flare nut. (Photo 11-5)

(5) Remove the pressure relief valve (3 bar) using two

spanners: one to hold the flare joint and the other to turn

the pressure relief valve (3 bar). (Photo 11-6)

(6) Eliminate loctite on the thread surfaces using remover.

(Photo 11-6)

•

Before reinstallation, apply loctite over the thread

surface on the pressure relief valve.

•

For more details about the loctite and the remover,

refer to Page 83.

<

Air vent (automatic)

>

(3) Remove the air vent (automatic) using two spanners:

one to hold the flare joint and the other to turn the flare

nut. (Photos 11-5)

(4) Remove the air vent with the flare joint. (Photo 11-5)
(5) Remove the flare joint from the air vent. (Photo 11-7)

<

Pressure relief valve (10 bar) (Except for EH*T20*-MHCW

models)

>

(3) Remove the field piping from the pressure relief valve

(10 bar). (Photo 11-8)

(4) Remove the pressure relief valve (10 bar) with the flare

joint using two spanners: one to hold the flare joint and

the other to turn the flare nut. (Photo 11-9)

(5) Remove the pressure relief valve (10 bar) using two

spanners: one to hold the flare joint and the other to turn

the pressure relief valve (10 bar). (Photo 11-10)

(6) Eliminate loctite on the thread surfaces using remover.

(Photo 11-10)

•

Before reinstallation, apply loctite over the thread

surface on the pressure relief valve.

•

For more details about the loctite and the remover,

refer to Page 83.

Photo 11-6

Photo 11-5

Photo 11-9

Photo 11-10

Photo 11-7

Air vent

Flare joint

Pressure relief
valve (3 bar)

Flare joint

Threads for application of loctite

From the previous page.

Photo 11-8 (Except for EH*T20*-MHCW models)

Air vent
(automatic)

Pressure relief
valve (3 bar)

Air vent
(automatic)

Pressure relief
valve (3 bar)

Pressure relief
valve (10 bar)

Flare joint

Flare nut

Pressure relief
valve (10 bar)

Flare joint

Threads for application of loctite

Flare joint

Flare nut

Flare joint

Flare nut

Pressure relief
valve (10 bar)

OCH570

DISASSEMBLY PROCEDURE

PHOTOS

75

Photo 13-1

13.

How to remove the temperature and pressure (T&P) relief
valve

(EH*T20*-MHCW models)

(1) Remove the front panel (Refer to Procedure 1).

(2) Swing the control box to the front (Refer to Procedure 4).
(3) Remove the field piping from the T&P relief valve.

(4)

Detach the quick connection. (Photo 13-1)

•

When reinstalling the quick connection, use a new O-ring.

• Refer to Procedure 23 for how to attach and detach the

quick connection.

(5) Remove the T&P relief valve using two spanners: one to

hold the T&P joint and the other to turn the T&P relief

valve. (Photo 13-2)

(6) Eliminate loctite on the thread surfaces using remover.

(Photo 13-2)

•

Before reinstallation, apply locktite over the thread sur-

face on the T&P relief valve and install the T&P relief
valve with the T&P joint.

• When reinstalling the T&P relief valve, point the nut to

the bottom as specified. (Photo 13-1)

• For more details about the loctite and the remover, refer
to Page 83.

12.

How to remove the expansion vessel

(1) Remove the front panel (Refer to Procedure 1).

(2) Swing the control box to the front (Refer to Procedure 4).

(3) Remove 2 tapes. (Photo 12-1)

• The removed tape can be disposed of.

(4) Remove the flare nut using two spanners: one to hold the

flare joint and the other to turn the flare nut. (Photo 12-1)

(5) Displace the pipe slightly downward and pull out the

expansion vessel. (Photo 12-1)

(6) Remove the flare joint from the expansion vessel. (Photo

12-2)

•

When reinstalling the flare joint, use a new G3/8" gasket.

Note: To avoid dropping of the expansion vessel, hold it

by hand when removing it.

Photo 12-1

T&P relief valve

14. How to remove the air vent (manual)

(1) Remove the front panel (Refer to Procedure 1).

(2) Remove the air vent (manual) by turning the air vent

(manual).

Air vent (manual)

Pipe

Flare joint Flare nut

Expansion vessel

Photo 12-2

Flare joint

Photo 13-2

Gasket (G3/8")

Photo 14

Tapes

Quick connection

O-ring

T&P joint T&P relief valve

Threads for application of loctite

OCH570

DISASSEMBLY PROCEDURE

PHOTOS

76

Photo 15-1

15. How to remove the drain cock (primary circuit)

(1) Remove the front panel (Refer to Procedure 1).

<Pump valve side>

(2) Remove the drain cock from the pump valve by turning

the drain cock. (Photo 15-1)

<Pipe side (for P-HEX)>

(2) Remove the drain cock from the pipe by turning the drain

cock. (Photo 15-1)

<Pipe side (EHPT20X models only)>

(2) Remove the drain cock from the pipe by turning the drain

cock. (Photo 15-2)

16.

How to remove the drain cock (sanitary circuit)

(1) Remove the front panel (Refer to Procedure 1).

<DHW tank side>

(2) Remove the drain cock by detaching the quick connection.

(Photo 16-1)

•

When reinstalling the quick connection, use a new
O-ring.

• Refer to Procedure 23 for how to attach and detach

the quick connection.

<P-HEX (Water-Water) side>

(2) Remove the drain cock from the P-HEX (Water-Water) by

turning the drain cock. (Photo 16-2)

Drain cock (DHW tank side)

Photo 16-1

Quick

connection

O-ring

Drain cock for P-HEX
(Pipe side)

Drain cock
(Pump valve side)

Photo 15-2

Drain cock
(Pipe side)

Photo 16-2

Drain cock
(P-HEX side)

P-HEX

OCH570

DISASSEMBLY PROCEDURE

PHOTOS

77

Nut

(G3/4")

Water
coil W
cover

Screw

Screw

Photo 17-1

Photo 17-2

17.

How to remove the plate heat exchanger (P-HEX)

<Water - Water>

(1) Remove the front panel (Refer to Procedure 1).

(2) Drain water in the P-HEX (Water-Water) using the drain

cock (Primary circuit) and the drain cock (Sanitary
circuit). (Photo 17-1)

(3) Remove the 2 screws to remove the water coil W cover.

(Photo 17-1)

•

Reuse the water coil W cover and the fixing screws.

(4) Remove the 4 G3/4" nuts.

•

When reinstalling the

nuts

, use new

G3/4" gaskets

.

(5) Remove the P-HEX (Water-Water) and drain cock

(Sanitary circuit). (Photo 17-2)

•

When reinstalling the

drain cock (sanitary circuit)

, use a

new

one

.

Gasket

(G3/4")

Nut (G3/4")

Gasket (G3/4")

Drain cock
(Sanitary circuit)

Drain cock
(Primary circuit)

Nut (G3/4")

Gasket (G3/4")

P-HEX (Water-Water)

Drain cock
(Sanitary circuit)

Nut

(G3/4")

Gasket

(G3/4")

18. How to remove the water pump (sanitary circuit)
(1) Remove the front panel (Refer to Procedure 1).

(2) Disconnect the CNP4 connector and the earth cable in

the control box. (Photo 4-2)

(3) Release the water pump lead wire from the 2 cable

clamps and the cable strap in the control box, the 2
cable straps and the 3 bands below the control box.

(Photos 4-1 and 10-1)

(4) Remove the water pump (sanitary circuit) by removing

the two G1" nuts using the 2 spanners, one to hold the
G1" nut and the other to turn the other side of G1" nut.

(Photo 18)

•

When reinstalling the G1" nuts, use a new G1" gaskets.

•

Set the water pump in the orientation of the arrow
printed on the water pump and in the way that the
terminal box faces to the left. (Photo 18)

•

Set the pump speed of the newly installed water pump

to "

". (Photo 18)

Photo 18

Nut (G1")

Gasket (G1")

Water pump
(Sanitary circuit)

Nut (G1")

Gasket (G1")

Terminal box

Flow

direction

Pump
speed:

P-HEX (Water-Water)
(inside)

OCH570

DISASSEMBLY PROCEDURE

PHOTOS

78

19. How to remove the scale trap (sanitary circuit)
(1) Remove the front panel (Refer to Procedure 1).
(2) Disconnect the CNP4 connector and the earth cable in

the control box. (Photo 4-1)

(3) Release the water pump lead wire from the 2 cable

clamps and the cable strap in the control box, the 2
cable straps and the 3 bands below the control box.

(Photos 4-1 and 10-1)

(4) Remove the P-HEX (Water-Water) (Refer to Procedure

17).

(5) Remove the 3 screws and the plate (under P-HEX

(W-W)). (Photo 19-1)

(6) Remove the pipe (Tank - P-HEX (W-W)) by removing the

G3/4" nut. (Photo 19-1)

•

When reinstalling the G3/4" nut, use a new G3/4" gasket.

(7) Remove the G3/4" nut and quick connection clip from the

pipe (W.P. - Tank).

(Photo 19-2)

•

When reinstalling the G3/4" nut, use a new G3/4" gasket.

(8) Remove the screw which fixes the S.T. support. (Photo

19-3)

• If there is not enough space to use a screw driver,
rotate the pipe (W.P. - Tank) forward with a use of the

quick connection part as a fulcrum.

(9)

Remove the 2 screws (Right side). (Photos 19-1 and 19-2)

(10) Remove the scale trap with the water pump, pipes and

the S.T. support.

(Photo 19-4)

(11) Remove the

G1" nut, the screws and the saddle band,

then remove the scale trap.

(Photo 19-4)

• When reinstalling the G1" nut, use a new G1" gasket.

• Reuse the saddle band and the screws.

• Reuse the

S.T. support.

Photo 19-1

Photo 19-2

Photo 19-3

Photo 19-4

Scale trap

Water pump

Nut (G1")

S.T. support

Screws

Saddle band

Pipe (Water pump

- DHW tank)

Nut (G3/4"),
Gasket (G3/4")

Pipe (Tank - P-HEX
(W-W))

Screws

Plate (under P-HEX
(W-W))

Screw fixing the

S.T. support

Nut (G3/4")

Pipe (W.P. - Tank)

Quick connection

clip

Water pump

Screw (right

side)

Screw fixing

the S.T.
support

Pipe
(W.P. - Tank)

Gasket (G1")

Screw
(right side)

OCH570

DISASSEMBLY PROCEDURE

PHOTOS

79

20. How to remove

the liquid refrigerant temp. thermistor
(TH2) / flow water temp. & return water temp. thermistor
(THW1,THW2) / tank water temp. thermistor (THW5)

(1) Remove the front panel (Refer to Procedure 1).

(2) Disconnect the following thermistor connectors on the

controller board and release the lead wires from cable

clamps and bands. (Photos 20-1 and 20-3)

•

TH2 (CN21) (cable clamp, 2 cable straps, coated clamp
and 3 bands)

• THW1, THW2 (CNW12) (cable clamp, 2 cable straps,

coated clamp and 2 bands)

• THW5 (CNW5) (

cable clamp, 2 cable straps, coated

clamp and 2 bands

)

(3) Remove the thermistors from the thermistor holders.

(Photos 20-1 and 20-2)

Photo 20-1

Thermistor
<THW1>

Thermistor
<THW5>

Thermistor <TH2> Band

Photo 20-3

Thermistor
connectors
CN21 <TH2>
CNW12 <THW1>, <THW2>
CNW5 <THW5>

Cable
clamp

Photo 20-2

Thermistor <THW2>

Cable
strap

Band

Band

Cable
strap

Coated
clamp

Cable
clamp

OCH570

DISASSEMBLY PROCEDURE

PHOTOS

80

Photo 21-1

21. How to remove the side panels

(1) Remove the front panel (Refer to Procedure 1).

(2) Remove the 4 screws on the top panel, and remove the

2 screws that hold the top panel onto the back panel.

(Photos 21-2 and 22-1)

(3) Remove the side panel (right) by removing the 7 screws

fixing the side panel (right). (Photo 21-1)

(4) Remove the side panel (left) by removing the 8 screws

fixing the side panel (left). (4 screws on the front side
and 4 screws on the back side)

<V/M plate (EH*T20*-MHCW models only)>

(1) Remove the V/M plate by removing 5 screws fixing on

the side panel (Right). (Photo 21-1)

Screws

Side panel (Right)

Screws

Side panel
(Left)

Screws

V/M plate

Photo 21-2

Screws

Screws

Top panel

OCH570

DISASSEMBLY PROCEDURE

PHOTOS

81

22.

How to remove the back panel

(1) Remove the front panel (Refer to Procedure 1).
(2) Remove the side panels (Refer to Procedure 21).

(3) Remove the 4 screws on the back panel, and remove the

2 screws that hold the back panel onto the frame. Then
pull out the back panel while lifting the top panel. (Photos

22-1 and 22-2)

Note:

The handles are removed by pushing them up.

Photo 22-1

Handles

Top panel

Screws

(Back panel)

Screws (Top panel)

Photo 22-2

Top panel

Screw

Back panel

The photo shows the left side.
The opposite side also has the screw to be

removed on the same position.

Screw (opposite side)

OCH570

82

PHOTOS & ILLUSTRATION

DISASSEMBLY PROCEDURE

O-ring

Plastic

bag

Female Male

O-ring

Photo 23-1

Photo 23-2

Photo 23-3

Photo 23-4

Photo 23-5

Photo 23-6 Photo 23-7 Photo 23-8

23. How to detach and attach the quick connection

Refer to the following steps when detaching and attaching the

quick connection.
(1) Remove the clip. (Photos 23-1 and 23-2)

(2) Separate the connected parts to remove the O-ring. (Photo

23-3)

• Do not reuse the removed O-ring.

• Wipe off if dirt or foreign matters are found on the sealing
surface where the O-ring touches.

(3)

Apply grease on the O-ring using a plastic bag, etc. (Photo

23-4)

(4) Attach the O-ring to the male part of quick connection. (Pho-

to 23-5)

• Keep the O-ring free from dirt or foreign matters.

(5)

Connect the male and female parts of the quick connection.
(Photo 23-6)

(6) Attach the clip. (Photo 23-7)

• Ensure to attach the wider diameter of the clip to the fe­male side. Failure to do so it may cause water leak at the

connected part. (Photo 23-8)

Clip

Clip

Gap

Clip

OCH570

83

Notes on replacing the parts

Replacement of the parts listed below requires the following procedure.
After the parts are removed, eliminate loctite on threads by applying loctite remover, apply new loctite, and then install and tighten the parts to the specied tighten­ing torques below. For details about recommended loctite and loctite remover, refer to Table 11-1, and for details about the replacement parts and their tightening

torques, refer to Table 11-2.

Table 11-1

Recommended Manufacturer No. Applied parts Note

Loctite Henkel Loctite 577 PRESSURE RELIEF VALVE (3bar

and 10bar)

Apply loctite all over from the end of external thread to the
second ridge. After installing the parts, x the parts for at least

30 minutes

Loctite 5776 TEMPERATURE AND PRESSURE

RELIEF VALVE

Loctite remover Henkel Loctite 7200

Gasket Remover

PRESSURE RELIEF VALVE (3bar
and 10bar) and TEMPERATURE
AND PRESSURE RELIEF VALVE

Spray loctite remover over sealant on the threads, let the seal-

ant sit until soft, and then eliminate it with a wire brush.

Note: When using the products above, refer to the appropriate manuals that come with the individual products.

Table 11-2

Part name *1

Recommended tightening
torque [Nm] *2

PRESSURE RELIEF VALVE 3bar 15 ± 1

PRESSURE RELIEF VALVE 10bar 15 ± 1

TEMPERATURE AND PRESSURE RELIEF VALVE 15 ± 1

*1. For more details about the listed parts refer to the parts catalog.
*2. Undertightening and overtightening the parts affect water seal life. Tighten the parts to the appropriate tightening torques.

When installing the parts that are not listed above, observe the tightening torques in accordance with Table

11-3

.

Always use a new O

-

ring or gasket.

Table 11-3

Size

[inch]

Recommended tightening torque

[Nm]

Gasket

G1/4" 8 ± 1

G3/8" 15 ± 1

G3/4" 36 ± 2

G1" 42 ± 2

G1 3/4" 10 ± 1

Packing Strainer cover 40 ± 2

O-ring

Flow sensor 30 ± 2

Air vent (Automatic) 15 ± 1

Attached packing

Drain cock (primary circuit) 0.25 ± 0.05

Drain cock

(P-HEX sanitary circuit)

0.25 ± 0.05

Air vent (manual) 0.25 ± 0.05

Flare joint (for water circuit parts) 35 ± 2

After the procedure is complete, ensure that no water leaks.

OCH570

84

12

SUPPLEMENTARY INFORMATION

Refrigerant collecting (pumpdown) for split model systems only

Refer to “Refrigerant collection” in the outdoor unit installation manual or service manual.

Back-up operation of boiler

Heating operation is backed up by boiler.

For more details, refer to the installation manual of PAC-TH011HT-E.

<Installation & System set up>

1. Set DIP-SW 1-1 to ON "With boiler" and SW2-6 to ON “With Mixing tank”.

2. Install the thermistors THWB1 (Flow temp.) and THWB2 (Return temp.) *1 on the boiler circuit.

3. Connect the output wire (OUT10: Boiler operation) to the input (room thermostat input) on the boiler. *2

4. Install one of the following room temperature thermostats. *3

Wireless remote controller (option)
Room temp. thermostat (local supply)
Main controller (remote position)

*1 The boiler temperature thermistor is an optional part.

*2 OUT10 has no voltage across it.
*3 Boiler heating is controlled on/off by the Room temp. thermostat.

<Remote controller settings>

1. Go to Service menu > Heat source setting and choose “Boiler” or “Hybrid”. *4

2. Go to Service menu > Operation settings > Boiler settings to make detailed settings for “Hybrid” above .

*4 The “Hybrid” automatically switches heat sources between Heat pump (and Electric heater) and boiler.

OCH570

85

13

SERVICE AND MAINTENANCE

(Continued to next page.)

Engineers Forms

Should settings be changed from default, please enter and record new setting in ‘Field Setting’ column. This will ease resetting in the future should the system use change

or the circuit board need to be replaced.

Commissioning/Field settings record sheet

Main controller screen Parameters Default setting

Field setting

Notes

Main Zone1 heating room temp. 10°C - 30°C 20°C

Zone2 heating room temp. *12 10°C - 30°C 20°C
Zone1 heating ow temp. 25°C - 60°C 45°C
Zone2 heating ow temp. *1 25°C - 60°C 35°C
Zone1 heating compensation curve −9°C - + 9°C 0°C
Zone2 heating compensation curve *1 −9°C - + 9°C 0°C

Holiday mode Active/Non active/Set time —

Option Forced DHW operation On/Off —

DHW On/Off/Timer On

Heating On/Off/Timer On
Energy monitor Consumed electrical energy/Delivered energy —

Setting DHW Operation mode Normal/Eco Normal

DHW max. temp. 40°C - 60°C *2 50°C
DHW temp. drop 5°C - 30°C 10°C
DHW max. operation time 30 - 120 mins 60 mins
DHW mode restriction 30 - 120 mins 30 mins

Legionella prevention Active Yes/No Yes

Hot water temp. 60°C - 70°C *2 65°C

Frequency 1 - 30 days 15 days
Start time 00.00 - 23.00 03.00

Max. operation time 1 - 5 hours 3 hours
Duration of maximum temp. 1 - 120 mins 30 min

Heating Zone1 operation mode Room temp/Flow temp/Compensation curve Room temp

Zone2 operation mode *1 Room temp/Flow temp/Compensation curve

Compensation

curve
Compensation
curve

Hi flow temp.

set point

Zone1 outdoor ambient temp. −30°C - +33°C *3 −15°C
Zone1 ow temp. 25°C – 60°C 50°C
Zone2 outdoor ambient temp. *1 −30°C - +33°C *3 −15°C

Zone2 ow temp. *1 25°C - 60°C 40°C

Lo ow temp.

set point

Zone1 outdoor ambient temp. −28°C - +35°C *4 35°C
Zone1 ow temp. 25°C - 60°C 25°C
Zone2 outdoor ambient temp. *1 −28°C - +35°C *4 35°C

Zone2 ow temp. 25°C - 60°C 25°C

Adjust Zone1 outdoor ambient temp. −29°C - +34°C *5 —

Zone1 ow temp. 25°C - 60°C —
Zone2 outdoor ambient temp. *1 −29°C - +34°C *5 —
Zone2 ow temp. *1 25°C - 60°C —

Holiday DHW Active/Non active Non active

Heating Active/Non active Active
Zone1 heating room temp. 10°C - 30°C 15°C
Zone2 heating room temp. *12 10°C - 30°C 15°C
Zone1 heating ow temp. 25°C - 60°C 35°C
Zone2 heating ow temp. *1 25°C - 60°C 25°C

Initial settings Language EN/FR/DE/SV/ES/IT/DA/NL/FI/NO/PT/BG/PL/

CS/RU

EN

°C/°F °C/°F °C
Summer time On/Off Off
Temp. display Room/DHW tank/Room&DHW tank /Off Off
Time display hh:mm/hh:mm AM/AM hh:mm hh:mm

Room sensor settings for Zone1 TH1/Main RC/Room RC1-8/“Time/Zone” TH1
Room sensor settings for Zone2 *1 TH1/Main RC/Room RC1-8/“Time/Zone” TH1
Room RC zone select *1 Zone1/Zone2 Zone1

Service menu Thermistor

adjustment

THW1 −10°C - +10°C 0°C
THW2 −10°C - +10°C 0°C
THW5 −10°C - +10°C 0°C
THW6 −10°C - +10°C 0°C
THW7 −10°C - +10°C 0°C
THW8 −10°C - +10°C 0°C
THW9 −10°C - +10°C 0°C
THWB1 −10°C - +10°C 0°C
THWB2 −10°C - +10°C 0°C

Auxiliary settings Economy settings for

pump.

On/Off *6 On
Delay (3 - 60 mins)

10 mins

Electric heater

(Heating)

Space heating: On (used)/Off (not used) On

Electric heater delay timer (5 - 180 mins) 30 mins
Electric heater
(DHW)

Booster heater

DHW: On (used)/Off (not used)

On

Immersion heater

DHW: On (used)/Off (not used)

On

Electric heater delay timer (15 - 30 mins) 15 mins
Mixing valve control Running (10 - 240 secs) 120 secs

Interval (1 - 30 mins) 2 mins

Flow sensor Minimum(0 - 100L/min.) 5 L/min.

Maximum(0 - 100L/min.) 100 L/min.

*1 The settings related to Zone2 can be switched only when 2 zone temperature control is enabled (when DIP SW2-6 and SW 2-7 are ON).
*2 For the model without both booster and immersion heater, it may not reach the set temperature depending on the outside ambient temperature.
*3 The lower limit is -15°C depending on the connected outdoor unit.
*4 The lower limit is -13°C depending on the connected outdoor unit.
*5 The lower limit is -14°C depending on the connected outdoor unit.

OCH570

86

(From the previous page.)

Engineers Forms

Commissioning/Field settings record sheet (continued from the previous page)

Main controller screen Parameters

Default
setting

Field
setting

Notes

Service
menu

Pump speed Pump speed(1 - 5) 5
Heat source setting Standard/Heater/Boiler/Hybrid *7 Standard
Operation

settings

Heating operation*8Flow temp.range

*10

Min.temp.(25 - 45°C) 30°C

Max.temp.(35 - 60°C) 50°C
Room temp.
control

Mode(Normal/Fast) Normal

Interval(10 - 60min.) 10min.
Heat pump

thermo diff.adjust

On/Off *6 On

Lower limit(−9 - −1°C) -5°C

Upper limit(+3 - +5°C) 5°C

Freeze stat function *11 Outdoor ambient temp. (3 - 20°C) / ** 5°C
Simultaneous operation (DHW/Heating)

On/Off *6 Off

Outdoor ambient temp. (−30 - +10°C) *4 −15°C

Cold weather function

On/Off *6 Off

Outdoor ambient temp. (−30 - −10°C) *4 −15°C

Boiler operation

Hybrid settings Outdoor ambient temp. (−30 -

+10°C) *4

−15°C

Priority mode (Ambient/Cost/
CO

2)

Ambient

Intelligent set-

tings

Energy

price
*9

Electricity
(0.001 - 999 */kWh)

0.5

*/kWh

Boiler
(0.001 - 999 */kWh)

0.5

*/kWh

CO2
emis­sion

Electricity

(0.001 -

999 kg -CO2/kWh)

0.5 kg -CO2/kWh

Boiler (0.001

- 999

kg -CO2/kWh)

0.5 kg -CO2/kWh

Heat
source

Heat pump capacity
(1

- 40 kW)

11.2

kW

Boiler efciency
(25

- 150%)

80%

Booster heater 1
capacity
(0

- 30 kW)

2 kW

Booster heater 2
capacity
(0

- 30 kW)

4 kW

Floor dry up function

On/Off *6 Off

Target temp. Start&Finish

(25 - 60°C) 30°C

Max. temp.

(25 - 60°C) 45°C

Max. temp. period

(1 - 20 days)

5 days

Flow temp.

(Increase)

Temp. increase step (+1 - +10°C)

+5°C

Increase interval (1 - 7 days)

2 days

Flow temp.

(Decrease)

Temp. decrease step (−1 - −10°C)−5°C

Decrease interval (1 - 7 days)

2 days

Energy

monitor

settings

Electric heater
capacity

Booster heater 1
capacity

0 - 30kW 2kW

Booster heater 2
capacity

0 - 30kW 4kW

Immersion heater
capacity

0 - 30kW 0kW

Delivered energy adjustment −50 - +50% 0%
Water pump input Pump 1 0 - 200W or ***(factory tted pump) ***

Pump 2 0 - 200W 0W
Pump 3 0 - 200W 0W

Electric energy meter 0.1/1/10/100/1000 pulse/kWh 1 pulse/kWh
Heat meter 0.1/1/10/100/1000 pulse/kWh 1 pulse/kWh

External in­put settings

Demand control (IN4) Heat source OFF/Boiler operation Boiler

operation

Outdoor thermostat (IN5)

Heater operation/Boiler operation Boiler

operation

*6 On: the function is active; Off: the function is inactive.
*7 When DIP SW1-1 is set to OFF “WITHOUT Boiler” or SW2-6 is set to OFF “WITHOUT Mixing tank”, neither Boiler nor Hybrid can be selected.
*8 Valid only when operating in Room temp. control mode.
*9 “*” of “*/kwh” represents currency unit (e.g. € or £ or the like)
*10 Valid only when operating in Heating room temperature.
*11 If asterisk (**) is chosen freeze stat function is deactived. (i.e. primary water freeze risk)
*12 The settings related to Zone2 can be switched only when 2-zone temperature control or 2-Zone valve ON/OFF control is active.

OCH570

87

Annual Maintenance Log Book

Contractor name Engineer name
Site name Site number

Cylinder unit maintenance record sheet
Warranty number Model number

Serial number

No. Mechanical Frequency Notes

1

Turn OFF water supply, drain DHW tank, remove mesh from strainer

clean and replace in strainer. *1

2

Keep water supply OFF, open hot water taps and check the primary-side
expansion vessel charge pressure. Top up if necessary (1 bar).

3

Keep water supply OFF and check the potable vessel charge pressure.

Top up if necessary (3.5 bar).

4

Keep water supply OFF. In hard water areas de-scaling of the immersion

heaters may be required.

5

Drop the primary/heating system pressure to zero check and if neces­sary top up the expansion vessel (1 bar). Air valve of expansion vessel is

TR-412.

6

Turn water supply ON, open the pressure relief valve and then the expan­sion relief valve in turn. Check for unrestricted discharge to the tundish
and that the valves reseat correctly. Check there are no blockages in the
tundish and associated pipework.

7

Check and if necessary top up the concentration of anti-freeze/inhibitor (if

used in the system).

8

Top up the primary/heating system using a temporary backow preven­tion lling loop and re-pressurise to 1 bar.

9

Heat system and check pressure does not rise above 3 bar and no water

is released from the safety valves.

10 Release any air from the system.

11

To check the 3-way valve for inside leaks, conrm that the temperature of
the heat emitter does not rise when running the DHW mode.
Refrigerant models only [except EHPT20 series] Frequency Notes

1 Refer to outdoor unit manual.

Electrical Frequency Notes
1 Check condition of cables.
2 Check rating and fuse tted on the electricity supply.

Controller Frequency Notes
1 Check eld settings against factory recommendations.
2 Check operation of motorized valves ensure they reseat correctly.
3 Check battery power of wireless thermostat and replace if necessary.

Outdoor heat pump unit maintenance record sheet
Model number Serial number

Mechanical Frequency Notes
1 Inspect grill and air inlet for trapped debris/damage.
2 Check condensate drain provision.
3 Check integrity of water pipework and insulation.
4 Check all electrical connections.
5 Check and record the operation voltage.

* Checks should be carried out once a year.

*1 Be sure to reattach the mesh after washing.

Note:Withintherstcoupleofmonths ofinstallation,remove andcleanthecylinderunit’sstrainer meshplusanythatare ttedexternalto thecylinder

unit. This is especially important when installing on an existing system.

In addition to annual servicing, it is necessary to replace or inspect some parts after a certain period of system operation. Please see tables below for detailed instruc­tions. Replacement and inspection of parts should always be done by a competent person with relevant training and qualications.

Parts which require regular replacement

Parts Replace every Possible failures

Pressure relief valve (PRV)
Air vent (Auto/Manual)
Drain cock (Primary/Sanitary circuit)
Manometer

Inlet control group (ICG)*

6 years Water leakage

*

OPTIONAL PARTS for UK

Parts which require regular inspection

Parts Check every Possible failures

Immersion heater 2 years

Earth leakage causing

circuit breaker to activate

(Heater is always OFF)

Water circulation pump 20,000 hrs (3 years)

Water circulation pump
failure

Parts which must NOT be reused when servicing

* O-ring

* Gasket

Note: Always replace the gasket for pump with a new one at each regular

maintenance (every 20,000 hours of use or every 3 years).

OCH570

HEAD OFFICE : TOKYO BLDG., 2-7-3, MARUNOUCHI, CHIYODA-KU, TOKYO 100-8310, JAPAN

Copyright 2014 MITSUBISHI ELECTRIC CORPORATION

Distributed in Dec. 2014 No. OCH570
Made in Japan

New publication, effective Dec. 2014
Specifications are subject to change without notice.