Viessmann Vitotronic 300, GW2 Installation And Service Instructions Manual

Installation and
Service Instructions

for use by heating contractor

Vitotronic 300, Model GW2

Outdoor-reset logic digital boiler and
heating circuit control unit

Please file in Service Binder

VITOTRONIC 300

Certified as a component part
of Viessmann boilers only

5285 941 v1.6 12/2012

IMPORTANT

Read and save these instructions
for future reference.

1

General information

Safety, Installation and Warranty Requirements

Please ensure that this manual is read and understood before commencing installation. Failure to comply with the issues

listed below and details printed in this manual can cause product/property damage, and/or severe personal injury. Ensure all
requirements below are understood and fulfilled (including detailed information found in manual subsections).

Licensed professional heating
contractor

The installation, adjustment, service,
and maintenance of this equipment
must be performed by a licensed
professional heating contractor.

Please see section
entitled “Important
Regulatory and
Installation
Requirements.”

Product documentation

Read all applicable documentation

before commencing installation. Store
documentation near boiler in a readily
accessible location for reference in the
future by service personnel.

For a listing of
applicable literature,
please see section
entitled “Important
Regulatory and
Installation Requirements.”

Advice to owner

Once the installation work is complete,
the heating contractor must familiarize
the system operator/ultimate owner
with all equipment, as well as safety
precautions/requirements, shut-down
procedure, and the need for
professional service annually before
the heating season begins.

Warranty

Information contained in
this and related product
documentation must be
read and followed. Failure

to do so renders warranty
null and void.

Safety Terminology

The following terms are used throughout this manual to bring attention to the presence of potential hazards or important
product information. Please heed the advice given!

DANGER

Indicates an imminently hazardous
situation which, if not avoided, will
result in death, serious injury or
substantial product / property damage.

2

WARNING

Indicates an imminently hazardous
situation which, if not avoided, could
result in substantial product/property
damage, serious injury or loss of life.

WARNING

Indicates an imminently hazardous
situation which, if not avoided, may
result in minor injury or product /
property damage.

IMPORTANT

Helpful hints for installation,
operation or maintenance which
pertain to the product.

5285 941 v.1.6

Product Information

Vitotronic 300, Model GW2

For installation in or mounting on
Viessmann boilers only.

Applicable to the following control
units

Order No. 7134 555, 7143 156, 7511 362 from
Serial No. 7143 000

Order No. 7134 555, 7143 156, 7511 362 from
Serial No. 7187 101

Order No. 7134 555, 7143 156, 7511 362 from
Serial No. 7248 248







General information

5285 941 v.1.6

3

Index

General information

Page

Safety Requirements 2

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Heating system types

Installation

Product information 3

System types for modulating boilers 6

System types for condensing boilers 12

Overview of electrical connections 18

Routing and strain relief of cables 21

Inserting the boiler coding card 22

Adjustment of the fixed high limit 23

Adjustment of the adjustable high limit 24

Connection of the outdoor temperature sensor 25

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Connection of the boiler temperature sensor
and other sensors 26

Connection of the pumps 30

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Connection of boiler return mixing-valve or
modulating valve actuator 32

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Making space for accessory adaptors on the DIN rail
(CM2 only) 34

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Start-up

Connections to plug aBÖ 35

Compiled failure alarm indicator 36

Connection of external equipment to plug aVD 38

Connection of external equipment to plug aVH 39

Connection of external controls 40

Connection of combustion air device 45

Connection of low water cut-off device 49

Burner connection, burner control wiring 51

Power supply connection, boiler control 55

Mounting the front part of the control unit 57

Opening the control unit 59

Procedure (overview) 63

Steps 64

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4

5285 941 v.1.6

Index

Page

Scanning service information

Troubleshooting

Functional description

Additional information

Overview of service levels 72

Temperatures, boiler coding cards and scanning 73

Scanning operating status information 77

Scanning and resetting the ”Service” display 78

Troubleshooting steps 79

Diagnosis 80

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

Boiler temperature control 86

Heating circuit control 87

DHW tank temperature control 90

Overview 92

Technical data 93

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

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System components 94

Coding 1 114

Coding 2 116

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Wiring diagram 135

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5285 941 v.1.6

5

Heating system types

Heating system types for modulating boilers

System type 1 – Single-boiler system with shunt pump for raising the return temperature

in conjunction with
Vitorond 200, VD2

C C

A1 M2 M3

202205222052

1

28
21

5

40

M2

2

20

52

29

17B
17A

3

90

41

146

143

T2

T1

M3

2

20

52

B

A Boiler with Vitotronic 300
B Domestic hot water tank
C Heating circuit with mixing valve

*1

On the Vitorond the boiler supply and return are at the rear of the boiler.

6

*1

A

plugs

! Outdoor temperature sensor
? M2 Supply temperature sensor,

mixing valve circuit 2

? M3 Supply temperature sensor,

mixing valve circuit 3

§ Boiler temperature sensor
% DHW tank temperature sensor
aJA Temperature sensor T1
aJB Temperature sensor T2
sÖ A1 Close mixing valves with

external heating circuit controls

sÖ M2 Heating circuit pump, mixing

valve circuit 2

sÖ M3 Heating circuit pump, mixing

valve circuit 3

sA DHW pump
sK DHW re-circulation pump
sL Shunt pump
fÖ Power supply connection,

120 VAC

fA Burner (1st stage)
gS M2 Mixing valve motor, mixing

valve circuit 2

gS M3 Mixing valve motor, mixing

valve circuit 3

lÖ Burner (2nd stage/modulating)
aVD Connection of external

equipment (see page 38)

aVH Connection of external

equipment (see page 39)

5285 941 v.1.6

Heating system types

Heating system types for modulating boilers

Possible applications

Heating systems with manifold
arranged close to the boiler. The boiler
water flow is required to be reduced.

Please note:

This circuit diagram represents a
recommendation only. It is the
responsibility of the customer and/or
the heating contractor to check that
this recommendation is complete and
fully functional. Three-phase equipment
must be connected via additional
power contactors.

When the return temperature falls
below the required minimum value,
the temperature sensor T2 switches
on the shunt pump. If the minimum
return temperature is not reached
despite raising the return temperature,
the flow must be reduced by at least
50% via the temperature sensor T1.

The shunt pump must be sized so that
bypassed water accounts for approx.
30% of the total flow rate of the
boiler.

(continued)

Temperature sensor T1

Wiring of the temperature sensor
T1 in heating systems with heating
circuit control units which are not
connected via the LON BUS to the
boiler control unit.
Coding required: ”4C : 2” – use
plug sÖ for closing the mixing
valves of the heating circuits
connected downstream.

sÖ A1 Close mixing valves

A Contactor relay, field supplied
B Heating circuit controls

connected downstream
Switch contact closed: signal
for ”close mixing valve”.

Available system accessories

Vitotrol remote control
Flue gas temperature sensor

Coding of
system type

00: 1 If no system circuit A1 is connected, set

02: 1 Set coding ”02: 2” for operation with

03: 0 Set coding ”03: 1” for oil-fired operation

4A: 0 –– Connection of the temperature sensor T1 at

4b: 0 –– Connection of the temperature sensor T2 at

Change required Automatic change

The system type is recognized automatically
coding ”00: 3”, ”00: 4”, ”00: 7” or ”00: 8”
(see page 101)

modulating burner

(re-setting is not possible)

when the sensors are connected

plug aJA;

Coding ”4A: 1” is set automatically

plug aJB;

Coding ”4b: 1” is set automatically

––

––

5285 941 v.1.6

7

Heating system types

Circuit Diagram 1

Single-boiler system with Therm-Control and three-way mixing valve

in conjunction with Vitorond 200, VD2A

A Heating circuit with mixing valves
B DHW tank

Plug

! Outdoor temperature sensor
?M2 Flow temperature sensor,

mixing valve

?M3 Flow temperature sensor,

mixing valve

§ Boiler water temperature

sensor

% DHW tank temperature sensor
aJA Therm-Control temperature

sensor

8

sÖM2 Heating circuit pump, mixing

valve

sÖM3 Heating circuit pump, mixing

valve

sÖA1 Closing the mixing valves with

external heating circuit control
units

sA DHW primary pump
sK DHW circulation pump

fÖ Power supply, 120 VAC

60 Hz
Install the main isolator in
accordance with regulations

fA Burner (stage 1)
gSM2 Mixing valve motor
gSM3 Mixing valve motor
lÖ Burner

(burner stage 2 / mod.)

aVD/aVH External connections

Please refer to the control
manual Vitocontrol-S,
VD2/CT3.

5285 941 v1.6

Heating system types

Circuit Diagram 1

(continued)

sÖ A1 Close mixing valves

A Contactor relay, field supplied
B Heating circuit controls

connected downstream
Switch contact closed: signal
for ”close mixing valve”.

Wiring diagram

Wiring of the Therm-Control in heating
systems with heating circuit control units
are not connected to the boiler control
unit via the LON.
Required coding:
Change “4C” to “2” - use the plug-in
connector 20 A1 to close the
downstream mixing valve. Change “0D”
to “1” - the Therm-Control acts on the
mixing valve of the downstream heating
circuits (for Vitotronic 200 and 300,
delivered condition).

5285 941 v1.6

9

Heating system types

Heating system types for modulating boilers

(continued)

System type 2 – Single-boiler system with shunt pump and return valve for raising the return temperature

in conjunction with
Vitorond 200, VD2

C C

M3

2

20

52

1

28
21

5

M2 M3

22052220

41

40

M2

2

20

52

A1

29

52

52

17B
17A

3

90

146

143

T2

T1

B

A Boiler with Vitotronic 300
B Domestic hot water tank
C Heating circuit with mixing valve

*1

On the Vitorond the boiler supply and return are at the rear of the boiler.

10

*1

A

plugs

! Outdoor temperature sensor
? M2 Supply temperature sensor,

mixing valve circuit 2

? M3 Supply temperature sensor,

mixing valve circuit 3

§ Boiler temperature sensor
% DHW tank temperature sensor
aJA Temperature sensor T1
aJB Temperature sensor T2
sÖ M2 Heating circuit pump, mixing

valve circuit 2

sÖ M3 Heating circuit pump, mixing

valve circuit 3

sA Circulation pump for heating

the DHW tank

sK DHW re-circulation pump
sL Shunt pump
fÖ Power supply connection,

120 VAC

fA Burner (1st stage)
gS A1 Mixing valve motor for raising

the return temperature

gS M2 Mixing valve motor, mixing

valve circuit 2

gS M3 Mixing valve motor, mixing

valve circuit 3

lÖ Burner (2nd stage/modulating)
aVD Connection of external

equipment (see page 38)

aVH Connection of external

equipment (see page 39)

5285 941 v.1.6

Heating system types

Heating system types for modulating boilers

Possible applications

Heating systems with distributor
arranged close to the boiler. The boiler
water flow is required to be reduced.

Please note:

This circuit diagram represents a
recommendation only. It is the
responsibility of the customer and/or
the heating contractor to check that
this recommendation is complete and
fully functional. Three-phase equipment
must be connected via additional
power contactors.

Available system accessories

Vitotrol remote control
Flue gas temperature sensor

Coding
system type

00: 1 If no system circuit A1 is connected, set

02: 1 Set coding ”02: 2” for operation with

03: 0 Set coding ”03: 1” for oil-fired operation

0C: 0 Set coding ”0C: 1” for continuous return

4A: 0 –– Connection of the temperature sensor T1 at

4b: 0 –– Connection of the temperature sensor T2 at

Change required Automatic change

coding ”00: 3”, ”00: 4”, ”00: 7” or ”00: 8”
(see page 114)

modulating burner

(re-setting is not possible)

temperature control

When the return temperature falls
below the required minimum value,
the temperature sensor T2 switches
on the shunt pump. If, as a result,
the required minimum return
temperature is not reached, the
return valve is proportionally closed
via the temperature sensor T1 and
the minimum return temperature is
assured.

The shunt pump must be sized so that
bypassed water accounts for approx.
30% of the total flow rate of the
boiler.

(continued)

The system type is recognized automatically

when the sensors are connected

––

––

––

plug aJA;

Coding ”4A: 1” is set automatically

plug aJB;

Coding ”4b: 1” is set automatically

5285 941 v.1.6

11

Heating system types

Heating system types for condensing boilers

System type 3 – Single-boiler system with Vitocrossal 300

C C

A1 M2 M3

20220

1

28
21

5

41

40

52220

90

143

M2

2

20

52

52

3

146

M3

2

20

52

B

A Boiler with Vitotronic 300
B Domestic hot water tank
C Heating circuit with mixing valve
D Neutralizing unit

D

A

plugs

! Outdoor temperature sensor
? M2 Supply temperature sensor,

mixing valve circuit 2

? M3 Supply temperature sensor,

mixing valve circuit 3

§ Boiler temperature sensor
% DHW tank temperature sensor
sÖ A1 Heating circuit without mixing

valve (if installed)

sÖ M2 Heating circuit pump, mixing

valve circuit 2

sÖ M3 Heating circuit pump, mixing

valve circuit 3

sA Circulation pump for heating

the DHW tank

sK DHW re-circulation pump
fÖ Power supply connection,

120 VAC

fA Burner (1st stage)
gS M2 Mixing valve motor, mixing

valve circuit 2

gS M3 Mixing valve motor, mixing

valve circuit 3

lÖ Burner (2nd stage/modulating)
aVD Connection of external

equipment (see page 38)

aVH Connection of external

equipment (see page 39)

5285 941 v.1.6

12

Heating system types

Heating system types for condensing boilers

Please note:

This circuit diagram represents a
recommendation only. It is the
responsibility of the customer and/or
the heating contractor to check that
this recommendation is complete and
fully functional. Three-phase equipment
must be connected via additional
power contactors.

Available system accessories

Vitotrol remote control
Flue gas temperature sensor

Coding
system type

00: 1 If no system circuit A1 is connected, set

02: 1 Set coding ”02: 2” for operation with

0d: 1 Set coding ”0d: 0” ––

Change required Automatic change

coding ”00: 3”, ”00: 4”, ”00: 7” or ”00: 8”
(see page 114)

modulating burner

The Vitocrossal 300 is operated with
modulating boiler water temperature
by means of the outdoor re-set boiler
control unit. Viessmann modulating
burner is operated through Vitotronic
control.

The boiler water temperature which
is established in the heating mode is
higher than the maximum heating
circuit supply temperature by an
adjustable difference.

(continued)

The system type is recognized automatically

when the sensors are connected

––

5285 941 v.1.6

13

Heating system types

Heating system types for condensing boilers

(continued)

System type 4 - Single-boiler system with Vitocrossal 300 with several heating circuits and one modulating supply
temperature heating circuit

M3

2

F

20

52

or

A1 M2 M3

20220

1

28
21

5

41

40

52220

90

143

C D

M2

2

20

52

52

3

146

M3

2

20

52

E

B

G

A Boiler with Vitotronic 300
B Domestic hot water tank
C Heating circuit with mixing valve
D Modulating supply temperature

heating circuit
or

E Underfloor heating circuit
F High limit thermostat (max. limit)
G Neutralizing unit

14

A

plugs

! Outdoor temperature sensor
? M2 Supply temperature sensor,

mixing valve circuit 2

? M3 Supply temperature sensor,

mixing valve circuit 3

§ Boiler temperature sensor
% DHW tank temperature sensor
sÖ A1 Heating circuit without mixing

valve (if installed)

sÖ M2 Heating circuit pump, mixing

valve circuit 2

sÖ M3 Heating circuit pump, mixing

valve circuit 3

sA Circulation pump for heating

the DHW tank

sK DHW re-circulation pump
fÖ Power supply connection

120 VAC

fA Burner (1st stage)
gS M2 Mixing valve motor, mixing

valve circuit 2

gS M3 Mixing valve motor, mixing

valve circuit 3

lÖ Burner (2nd stage/modulating)
aVD Connection of external

equipment (see page 38)

aVH Connection of external

equipment (see page 39)

5285 941 v.1.6

Heating system types

Heating system types for condensing boilers

Possible applications

For heating circuits with different
temperatures.

Please note:

This circuit diagram represents a
recommendation only. It is the
responsibility of the customer and/or
the heating contractor to check that
this recommendation is complete and
fully functional. Three-phase equipment
must be connected via additional
power contactors.

The Vitocrossal 300 is operated with
modulating boiler water temperature
by means of the outdoor re-set boiler
control unit. Two-stage or modulating
burners can be controlled.

The Vitocrossal 300 has two return
connections. The heating circuits with
the higher return temperature are
connected to the return connection
at the top, those with the lower
temperatures to the return connection
at the bottom. Please note: At least
15% of the take-off from the rated
output must be connected to the
return connection at the bottom.

The boiler water temperature which
is established in the heating mode is
higher than the maximum heating
circuit supply temperature by an
adjustable difference.

(continued)

Pumps in the underfloor heating
circuit

20

20

LN

A B C

sÖ Heating circuit control unit

A Primary pump of underfloor

heating circuit

B High limit thermostat (max. limit)
C Secondary pump of underfloor

heating circuit (after system
separation)

Coding
system type

00: 1 If no system circuit A1 is connected, set

02: 1 Set coding ”02: 2” for operation with

0d: 1 Set coding ”0d: 0” ––

5285 941 v.1.6

Change required Automatic change

The system type is recognized automatically
coding ”00: 3”, ”00: 4”, ”00: 7” or ”00: 8”
(see page 114)

modulating burner

when the sensors are connected

––

15

Heating system types

Heating system types for condensing boilers

System type 5 – Single-boiler system with Vitocrossal 200

A Boiler with Vitotronic 300
B Domestic hot water tank
C Heating circuit with mixing valve
D Neutralizing unit

16

plugs

! Outdoor temperature sensor
? M2 Supply temperature sensor,

mixing valve circuit 2

? M3 Supply temperature sensor,

mixing valve circuit 3

§ Boiler temperature sensor
% DHW tank temperature sensor
sÖ A1 Heating circuit without mixing

valve (if installed)

sÖ M2 Heating circuit pump, mixing

valve circuit 2

sÖ M3 Heating circuit pump, mixing

valve circuit 3

sA Circulation pump for heating

the DHW tank

sK DHW re-circulation pump
fÖ Power supply connection,

120 VAC

fA Burner (1st stage)
gS M2 Mixing valve motor, mixing

valve circuit 2

gS M3 Mixing valve motor, mixing

valve circuit 3

lÖ Burner (2nd stage/modulating)
aVD Connection of external

equipment (see page 38)

aVH Connection of external

equipment (see page 39)

5285 941 v.1.6

Heating system types

Heating system types for condensing boilers

Please note:

This circuit diagram represents a
recommendation only. It is the
responsibility of the customer and/or
the heating contractor to check that
this recommendation is complete and
fully functional. Three-phase equipment
must be connected via additional
power contactors.

Available system accessories

Vitotrol remote control

Coding
system type

00: 1 If no system circuit A1 is connected, set

02: 1 Set coding ”02: 2” for operation with

0d: 1 Set coding ”0d: 0” ––

Change required Automatic change

coding ”00: 3”, ”00: 4”, ”00: 7” or ”00: 8”
(see page 114)

modulating burner

The Vitocrossal 200 is operated with
modulating boiler water temperature
by means of the outdoor re-set boiler
control unit. Viessmann modulating
burner is operated through Vitotronic
control.

The boiler water temperature which
is established in the heating mode is
higher than the maximum heating
circuit supply temperature by an
adjustable difference.

(continued)

The system type is recognized automatically
when the sensors are connected

––

5285 941 v.1.6

17

Installation

Overview of electrical connections

52

M3

52

M2

20

M3

20

M2

2

M3

2

M2

145
145

1

17

B

17

A

5

3/2

15

143

146

28
21
52
20
29
50

40
156
156

A1
A1

151

90

41

150

Mixing valve extension circuit board

? M2/M3 Supply temperature sensor
sÖ M2/M3 Heating circuit pump
gS M2/M3 Mixing valve motor

18

Low-voltage motherboard

! Outdoor temperature sensor

(ATS)

§ Boiler temperature sensor (BTS)
% DHW tank temperature sensor

(STS)

aG Flue gas temperature sensor

(AGS) (accessory)

aJA Therm-Control temperature

sensor
or
return temperature sensor T1
(RLS) (accessory)

aJB Return temperature sensor T2

(RLS) (accessory)

aVD Connection of external

equipment

aVG KM BUS participant, e.g.

Vitotrol remote control
(accessory)

aVH Connection of external

equipment

Line voltage motherboard

sÖ A1 Heating circuit pump or

control output

sA Circulation pump for heating

the DHW tank (accessory)

sK DHW re-circulation pump

(provided by customer)

sL Shunt pump
fÖ Power supply connection
fA Burner (1st stage)
gÖ Central fault indicator
gSA1 Continuous return

temperature control
or
3-way mixing valve for DHW
tank loading system

lÖ Burner (2nd stage/modulating)
aBÖ Connection of external

equipment, e.g. additional
safety equipment

aBA Safety circuit, potential free
aBH Power supply connection for

accessories

5285 941 v.1.6

Overview of electrical connections(for VD2/VD2A/CT3 only)

Installation

5285 941 v.1.6

19

Installation

Overview of electrical connections (for CM2 only)

20

5285 941 v.1.6

Routing and strain relief of cables

1. Run the cables from the connection enclosure into the control unit.

2. Apply strain relief to cables (see below).

Installation

Cables with moulded strain relief
clamp

Connect cable and strain relief
clamp.

OR

Fasten cable to the cable lead with
cable tie.

5285 941 v.1.6

21

Installation

Inserting the boiler coding card

CAUTION

For matching the operation of the
control unit to the boiler, only the
boiler coding card which is supplied
as part of the standard delivery of
the boiler may be used.

Only use the boiler coding card included with the boiler.

Boiler Coding card Part No.

Vitocrossal 300, type CT3 1040 7820 144

Vitorond 200, VD2 / VD2A 1020 7820 142

Vitocrossal 200 CM2 1041 7820 145

1. Push the boiler coding card
through the recess in the cover
and insert it in plug-in location
”X7”.

22

5285 941 v.1.6

Installation

Adjustment of the fixed high limit

The fixed high limit is supplied with a factory setting of 110°C / 230°F.

3.

(if required)

A

Adjustment to 99°C / 210°F

¨ Disconnect power to control

and burner!

1. Unclip the fuse box and swing

upwards.

2. Turn the slotted screw on the
rear of the fixed high limit until
the slot points to 99°C / 210°F
(once adjusted, the fixed high limit

cannot be reset to 110°C/ 230°F).

3. Re-fit the fuse box.

WARNING

If adjusted to 99°C / 210°F, do
not set the adjustable high limit
above 75°C / 167°F.

Please note:

Adjustment is required for the

1.

Vitocrossal 300.

See Service Instructions
for Vitocrossal 300.

2.

Non-condensing boiler
(VD2/VD2A) °C / °F

Fixed high limit 110 / 230 99 / 210 99 / 210 99 / 210

Adjustable high limit 100 / 212 95 / 203 95 / 203 95 / 203

Coding for the electronic maximum
temperature limiter of Vitotronic 100;
set code 06 to the temperature as
shown or less

93 / 200 87 / 188 87 / 188 88 / 190

Condensing boiler
(CT3) °C / °F

Condensing boiler
(CM2) °C / °F

5285 941 v.1.6

23

Installation

Adjustment of the adjustable high limit

The adjustable high limit is supplied with a factory setting of 95°C.

A

3.

2.

(if required)

Adjustment to 100°C / 212°F

1. Using a suitable screwdriver,

lever out and remove the
selector knob ”R” behind the
hinged cover.

2. Using a pair of pointed pliers,
break off the cams identified by
the shaded areas in the Fig.
from the stop dial.

A 75 to 100°C

167 to 212°F

3. Fit the selector knob ”R” so
that the marking is in the centre
of the selected range.

Please note:

Note the setting of coding address
”06”!

1.

WARNING

If the system is operated in
conjunction with a domestic hot
water tank, ensure that the
maximum permissible domestic
hot water temperature is not
exceeded. If necessary, install a
suitable safety device for this
purpose.

24

5285 941 v.1.6

Connection of the outdoor temperature sensor

The outdoor temperature sensor should be mounted 2 to 2.5 metres / 6.5 to
8 ft above ground level on the north or north-west facing wall of the building.
In the case of multi-storey buildings, it should be mounted in the upper half of
the second storey.
Make sure that the sensor is not located over windows, doors and air vents,
nor immediately beneath a balcony or guttering.
Do not paint over the outdoor temperature sensor housing.

1.

5.

3.

Installation

1. Remove the cap.

2. Mount the bottom part of the

sensor housing.

3. Pull the sensor wire through the
opening in the terminal
compartment and through the
strain relief provided.

4. Connect the wires to the
terminals.

600

580

560

540

520

500

480

460

4.

2.

5. Place the cap over the outdoor
temperature sensor.

WARNING

When extending wire, there is the
possibility of exposure to
electromagnetic interference. Avoid
running wires beside or near high
voltage 120/240 VAC conductors.
If proximity to high voltage
conductors cannot be avoided, use
stranded, twisted pair or shield design
wire. Ensure that only one end of the
shielding is grounded.

440

420

Resistance in

400

-40 -30 -20 -10 0 10 20 30

-40 -22

Outdoor temperature sensor °C / °F

5285 941 v.1.6

-4

14 32 50 68 86

25

Installation

Connection of the boiler temperature sensor

The sensor measures the boiler
water temperature.

3

760

740

The boiler temperature sensor is
installed at the same time as the
boiler insulation.

Check the sensor

1. Disconnect plug § in the

terminal compartment of the
boiler control.

2. Measure resistance of sensor
at terminals ”1” and ”2” of the
plug.

Boiler water
temperature
in °C / °F

40 / 104
50 / 122
60 / 140

3. Compare the value measured
with the current temperature.
If the value differs significantly,
check installation and, if
necessary, replace sensor.

Resistance
in ΩΩΩΩ

578
597
616

720

700

680

660

640

620

Resistance in

600

580

560

4000540

32 68 141 176 212 248 284104

Boiler temperature in

Technical data

Degree of protection: IP 32
Ambient temperature
During operation:

0 to + 130°C

32 to + 266°F

During storage and transport:

-20 to + 70°C

-4 to + 158°F

Electrical connection

The sensors are ready to plug in.
Insert the boiler temperature
sensor in socket ”3” of the boiler
control.

20 40 60 80 100 120 140

°C / °F

26

5285 941 v.1.6

Connection of the DHW tank temperature sensor

Installation

The sensor measures the domestic hot
water tank temperature.

5

sensor and tank
temperature sensor

720

Heating systems with domestic hot
water heating (single-boiler systems
only)

1. Install the DHW tank temperature

sensor.

See Installation
Instructions for domestic
hot water tank.

Please note:

When installing the sensor in DHW
tanks of other makes, make sure
that the sensor is pressed against
the sensor well of the DHW tank
by means of a suitable device.

2. Ensure that the maximum
permissible domestic hot water
temperature is not exceeded. If
necessary, install a suitable safety
device for this purpose.

Heating systems without domestic
hot water heating

Do not connect the DHW tank
temperature sensor.

Check the sensor

1. Disconnect plug % in the

terminal compartment of the
boiler control.

2. Measure resistance of sensor
at terminals ”1” and ”2” of the
plug.

DHW tank
temperature
in °C / °F

40 / 104
50 / 122
60 / 140

3. Compare the value measured
with the current temperature.
If the value differs significantly,
check installation and, if
necessary, replace sensor.

Technical data

Degree of protection: IP 32
Ambient temperature
During operation:

0 to + 90 °C

32 to + 194 °F

During storage and transport:

-20 to + 70 °C

-4 to + 158 °F

Resistance
in ΩΩΩΩ

578
597
616

700

Electrical connection

680

660

640

620

The sensors are ready to plug in.
Insert the DHW temperature
sensor in socket ”5” of the boiler
control.

Resistance in

600

580

560

540

0 20 40 60 80 100
32 68 104 140 176 212

DHW tank temperature in ºC / ºF

5285 941 v.1.6

27

Installation

740

R

e

s

i

s

t

a

n

c

e

i

n

Connection of the return temperature sensor

Strap-on temperature sensor and immersion temperature sensor

17A or 17B

17A or 17B

For measuring the boiler return
temperature.

Electrical connection

The sensor is inserted in socket
”17A” or ”17B” on the boiler
control.

Check the sensor

1. Disconnect plug aJA or aJB

in the terminal compartment of
the boiler control.

2. Measure resistance of sensor
at terminals ”1” and ”2” of the
plug.

720

700

680

660

640

620

Return
temperature
in °C / °F

30 / 86
40 / 104
60 / 140

3. Compare the value measured
with the current temperature. If
the value differs significantly,
check installation and, if
necessary, replace sensor.

Technical data

Degree of protection: IP 32
Ambient temperature
During operation:

0 to + 100°C

32 to + 212°F

During storage and transport:

-20 to + 70°C

-4 to + 158°F

Resistance
in ΩΩΩΩ

569
592
643

600

580

560

540

28

30 40 50 60 7070 80 90

20 100
68 86 104 122 140 158 176 194 212

Return temperature in

°C / °F

5285 941 v.1.6

Connection of the flue gas temperature sensor (VD2/VD2A/CT3 only)

The sensor measures the flue gas
temperature and monitors the
selected limit value.

Electrical connection

The sensor is inserted in socket
”15” on the boiler control.

Check flue gas temperature sensor

1. Disconnect plug aG in the

terminal compartment .

2. Measure resistance of sensor
at terminals ”1” and ”2” of the
plug.

Installation

1020

980

940

900

860

820

Ω

Ω

Ω

Ω

780

740

700

Resistance in

660

Flue gas
temperature
in °C / °F

180 / 176

160 / 320
200 / 392

3. Compare the value measured
with the actual temperature If
the value differs significantly,
check installation and, if
necessary, replace sensor.

Technical data

Degree of
protection: IP 60
Ambient temperature
During operation:

0 to + 600°C

32 to + 1112°F

During storage and transport:

-20 to + 70°C

-4 to + 158°F

Resistance
in ΩΩΩΩ

650
800
880

620

580

540

500

0

40 80

32 104 176

Flue gas temperature in °C / °F

5285 941 v.1.6

120 160 200 240 280
248 360 392 464 536

29

Installation

Connection of the Pumps (VD2/VD2A/CT3 only)

Available pump connections

sÖ A1/M1Heating circuit high

temperature (without mixing valve)

Terminals 5 - L, - G , - N

sA Circulation pump for heating

up the domestic hot water tank ­Terminals 4 - L, - G , - N

sL Shunt pump, boiler circuit pump

Terminals 6 - L, - G, - N.

sK

DHW recirculattion pump

terminals 3 - L, - G, - N

sÖM2

M2 Heating circuit high
temperature (with mixing valve)
Terminals 2 - L, - G , - N

sÖM3

M3 Heating circuit high
temperature (with mixing valve)
Terminals 1 - L, - G , - N

Install pumps: see
manufacturer’s
instructions.

120 VAC pumps

Note:

The maximum power consumption of
all pumps is 4A .
Rated current: max. 2 FLA
Recommended connection
cable: AWG 14

Use contactor for pumps with higher
current rating

Connect the 3-wire cable from the
pump to the corresponding terminals.

240 VAC or 3 PH pumps

Please note:

Use contactor and/or motor starter to
power pump.
For activating the contactor:
Rated current: max. 2 FLA
Recommended connection
wire size: AWG 14

Please ensure that all connections and
wire sizes comply with local and
national codes.

1.Select the contactor and the
connecting wire in accordance with
the rating of the pump that is to be
connected.

2.Connect pump and power supply to
the contactor.

3.Connect contactor coil to the
corresponding terminals.

30

5285 941 v1.6

Connection of the Pumps (CM2 only)

Available pump connections

Installation

sÖ A1/M1Heating circuit high

temperature (without mixing valve)

Terminals 7 - L, - G , - N

sA Circulation pump for heating

up the domestic hot water tank ­Terminals 6 - L, - G , - N

sL Shunt pump, boiler circuit pump

Terminals 8 - L, - G, - N.

sK

DHW recirculattion pump

terminals 5 - L, - G, - N

sÖM2

M2 Heating circuit high
temperature (with mixing valve)
Terminals 4 - L, - G , - N

sÖM3

M3 Heating circuit high
temperature (with mixing valve)
Terminals 3 - L, - G , - N

Install pumps: see
manufacturer’s
instructions.

120 VAC pumps

Note:

The maximum power consumption of
all pumps is 4A .
Rated current: max. 2 FLA
Recommended connection
cable: AWG 14

Use contactor for pumps with higher
current rating

Connect the 3-wire cable from the
pump to the corresponding terminals.

240 VAC or 3 PH pumps

Please note:

Use contactor and/or motor starter to
power pump.
For activating the contactor:
Rated current: max. 2 FLA
Recommended connection
wire size: AWG 14

Please ensure that all connections and
wire sizes comply with local and
national codes.

1.Select the contactor and the
connecting wire in accordance with
the rating of the pump that is to be
connected.

2.Connect pump and power supply to
the contactor.

3.Connect contactor coil to the
corresponding terminals.

5285 941 v1.6

31

Installation

Connection of boiler return mixing valve or modulating valve actuator

(VD2/VD2A/CT3 only)

1 120V or 24V valve adaptor

2 DIN rail in connection enclosure

3 aBH Terminals

120V valve adaptor

Rated voltage: 120 VAC
Rated current: max. 0.1 FLA
Recommended connection
wire size: AWG 14
Part No.: 7134 560

24V valve adaptor

Rated voltage: 24 VAC
Rated current: max. 0.15 FLA
Recommended connection
wire size: AWG 14
Part No.: 7134 559

Operating time:

5 to 199 sec. selected via coding
address “40”.

1 120V valve adaptor

2 120V valve actuator

1 24V valve adaptor

2 24V valve actuator

1. Disconnect power to control.

2. Install 120V or 24V valve
adaptor on DIN rail inside
connection enclosure.

3. Insert the plug gS into socket
gS on the control.

4. Fasten cable with tie.
(see page 21).

5. Connect black wire of the
adaptor to connection aBH on
the DIN rail.

- Terminal 8,9 or 10.

6. Connect valve actuator wires to
the adaptor terminals as shown
in figures.

32

5285 941 v.1.6

Installation

Connection of Boiler Return Mixing Valve or Isolation/Modulating Valve

(CM2 only)

10 11 12

1 120V or 24V Valve Adaptor

2 Junction box

3 120V L out power supply

120V Valve Adaptor

Rated voltage: 120 VAC
Rated current: max. 0.1 FLA
Recommended connection
wire size: AWG 14
Part No. 7511367

24V Valve Adaptor

Rated voltage: 24 VAC
Rated current: max. 0.15 FLA
Recommended connection
wire size: AWG 14
Part No. 7511366

Operating time:

5 to 199 sec. selected via coding
address “40”.

1 120V Valve Adaptor

2 120V valve actuator

1 24V Valve Adaptor

2 24V valve actuator

1. Disconnect power to control.

2. Install 120V or 24V Valve
Adaptor on DIN rail inside
connection enclosure.

3. Insert the plug gS into socket
gS on the control.

4. Fasten cable with tie
(see page.21).

5. Connect black wire of the
adaptor to connection 120V L
out the DIN rail

- Terminals 10,11 or 12.

6. Connect valve actuator wires
to the adaptor terminals as
shown on figures.

5285 941 v1.6

33

Installation

Making Space for Accessory Adaptors on the DIN Rail (CM2 only)

1. Push up on the bottom front of

the DIN rail clamp to remove and
set aside.

2. Using a flat head screwdriver,
remove the 4 ’spare’ DIN
terminals 23, 24, 25 and 26 one
at a time. Place the screwdriver
between the rail and the base of
the terminal and turn the
screwdriver clockwise . Discard
the removed terminals.

3. Re-install the DIN rail clamp by
hooking the latch of the clamp
around the top of the rail and then
push down on the front of the
clamp.

Note: See separate Installation

Instructions for accessory

adaptors.

34

5285 941 v1.6

Connections to terminal aBÖ (VD2/VD2A/CT3 only)

Installation

External shut-off

1. Remove jumper between

terminals 16 and 17.

2. Connect dry contact.
Controlled switch-off takes
place when the contact is
opened.

WARNING

The terminals should be used for
safety switch-off purposes only
(e.g. through a high limit thermostat).
Start at page 52 for details of
controlled switch-off.
During switch-off, there is no frost
protection of the heating system
and the boiler is not kept at the
minimum boiler water temperature.

A Jumper
B External shut-off (dry contact)

Emergency operation

Move jumper from terminals 16
and 17 to terminals 17 and 18.

5285 941 v.1.6

35

Installation

Connection of the compiled failure alarm indicator (VD2/VD2A/CT3 only)

Rated voltage: 120 VAC 60 Hz

A

B

Rated current: max. 2 FLA
Recommended connection
wire size: AWG 14

1. Disconnect power to control
and burner.

2. Connect the compiled failure
alarm as shown in the diagram.

A Connect terminal strip in

connection enclosure of boiler
control.

B Visual ond/or audible alarm

device (120 VAC).

36

5285 941 v.1.6

Connection of the compiled failure alarm indicator (CM2 only)

Installation

9

A

B

Rated voltage: 120 VAC 60 Hz
Rated current: max. 2 FLA
Recommended connection
wire size: AWG 14

1. Disconnect power to control
and burner.

2. Connect the compiled failure
alarm as shown in the diagram.

A Connect terminal strip in

connection enclosure of boiler
control.

B Visual ond/or audible alarm

device (120 VAC).

5285 941 v.1.6

37

Installation

address”64”

Connection of external equipment to terminal aVD

A

External changeover of the heating
program/”Open mixing valves”

Connect floating contact to terminals
”1” and ”2”.

B

143

A External changeover of the heating program/

”Open mixing valves” externally (floating contact)

B External disable/”Close mixing valves” externally

(floating contact)

The manually preselected heating
program can be changed over (see
table) and the mixing valves opened
via the contact.

Via coding address ”9A” the function
”Open mixing valves” and via coding
address ”91” the changeover of the
heating program can be assigned to
the heating circuits.

External disable/”Close mixing valves”

Connect floating contact to terminals
”2” and ”3”.

Controlled switch-off of the burner
takes place or the mixing valves are
closed when the floating contact is
closed.
The shunt pump is switched off.

Please note:

During controlled switch-off or
”Close mixing valves”, there is no
frost protection of the boiler or
heating circuits and no minimum
boiler water temperature is
maintained.

Manually preselected heating program

(with contact open)

9

or

w

or
rw Space heating ON/DHW ON

38

Space heating OFF/DHW OFF d5: 0

Space heating ON/DHW ON d5: 1 <–>

Coding address ”99” can be used to
select the equipment for which the
input aVD is to be effective.

Coding 2 Heating program after changeover

(with contact closed)

<–> Continuous operation with reduced room

(factory default)

temperature/DHW OFF

Continuous operation with normal room
temperature/DHW according to coding
address ”64”

5285 941 v.1.6

Connection of external equipment to plug aVH

B

A

Installation

External demand

Connect floating contact to
terminals ”2” and ”3”.

The burner of the boiler is switched
in on a load-dependent basis when
the floating contact is closed.

The boiler water temperature is
limited by the preset max. boiler
water temperature or by the value
set on the mechanical adjustable
high limit.
The required boiler set-point value is
set via the coding address ”9b”.

146

A External demand (floating contact)
B External changeover,

staged/modulating burner
(floating contact)

External changeover between
staged/modulating burner

Connect floating contact to
terminals ”1” and ”2”.

Contact open: modulating

operation

Contact closed: two-stage

operation

The burner type must be set to
”modulating” in coding 1
(coding ”02: 2”).

Please note:

When the burner type is scanned,
”modulating” continues to be
displayed after external changeover
(the display is not changed).

5285 941 v.1.6

39

Installation

Connection of external controls

Operation with two-stage burner

Settings on the control unit

The settings for the fixed high limit and
the other settings are dependent on the
safety equipment installed in
accordance with applicable codes.

Non-condensing boiler
(VD2/VD2A) °C / °F

Fixed high limit 110 / 230 99 / 210 99 / 210 99 / 210

Adjustable high limit 100 / 212 95 / 203 95 / 203 95 / 203

Coding for the electronic maximum
temperature limiter of Vitotronic 100;
set code 06 to the temperature as
shown or less

93 / 200 87 / 188 87 / 188 88 / 190

Single-boiler systems:

Coding ”01: 1”
(factory setting)

When a building automation system is
connected, only the connections on
plug aVD are required. The DHW tank
control unit is activated when the DHW
tank temperature sensor is connected.
The boiler water temperature must be
set to the minimum value.

Condensing boiler
(CT3) °C / °F

Multi-boiler systems:

Set coding ”01: 3”

When a building automation system
is connected, the connections on
plugs aVD and aVH are required.
The DHW tank temperature and the
load-dependent cascade control must
be controlled through the building
automation system.

Condensing boiler
(CM2) °C / °F

40

CAUTION

The boiler activation contact is
essential on multi-boiler systems.
The contact on the lead boiler MUST
be constantly closed.

5285 941 v.1.6

Installation

Connection of external controls (VD2/VD2A only)

Modulating boilers – operation with external modulation controller

1st stage burner fA from Vitotronic.

Plug lÖ from Vitotronic via

modulation controller (BAS).

On the bulding automation unit with

modulation controller set the
minimum temperatures 5°C / 9°F
above the minimum boiler water
temperature of the boiler.

(continued)

Boiler activation, isolation valve
open or closed

Connect dry contact at terminals
”2” and ”3” of the plug aVH.

Contact closed:
First, the preheat function for follow­up boilers is activated (coding
address ”2b”).
When the preheat function finishes,
the minimum temperature is
maintained for the boiler, and the
burner stages/modulation can be
switched externally.
The boiler water temperature is
limited by the preset maximum
boiler water temperature or via the
mechanical adjustable high limit.
The setpoint value is selected via
the coding address ”9b”.

Contact open:
The isolation valve is closed after
approx. 5 minutes (coding address
”2C”).
External override of the burner
stages is not possible, and no
minimum temperature is maintained.

Switch on 1st stage burner (basic
load)

Connect dry contact at terminals ”1”
and ”2” of the plug aVD.

Contact closed:
The 1st stage burner is switched on.
The full load is only switched on to
maintain the minimum temperature
(not with Vitocrossal 300). The
boiler water temperature is limited
by the electronic maximum
temperature limit (coding address
”06”) if this is set below the value
preset on the mechanical adjustable
high limit ”R”.

Contact open:
The 1st stage burner is switched
off.

5285 941 v.1.6

41

Installation

Connection of external controls (VD2/VD2A only)

Modulating boilers – operation with external modulation controller (continued)

Settings on the control unit

The settings for the fixed high limit and
the other settings are dependent on the
safety equipment installed in
accordance with applicable codes.

Non-condensing boiler
(VD2/VD2A) °C / °F

Fixed high limit 110 / 230 99 / 210 99 / 210 99 / 210

Adjustable high limit 100 / 212 95 / 203 95 / 203 95 / 203

Coding for the electronic maximum
temperature limiter of Vitotronic 100;
set code 06 to the temperature as
shown or less

93 / 200 87 / 188 87 / 188 88 / 190

Single-boiler systems:

Coding ”01: 1”
(factory setting)

Condensing boiler
(CT3) °C / °F

(continued)

Condensing boiler
(CM2) °C / °F

Multi-boiler systems:

Set coding ”01: 3”

When a building automation system is
connected, only the connections on
plug aVD are required. The DHW tank
control unit is activated when the DHW
tank temperature sensor is connected.
The boiler water temperature must be
set to the minimum value.

When a building automation
system is connected, the
connections on plugs aVD and
aVH are required.
The DHW tank temperature and
the load-dependent cascade control
must be controlled through the
external building automation
system.

CAUTION

The boiler activation contact is
essential on multi-boiler systems.
The contact on the lead boiler
MUST be constantly closed.

42

5285 941 v.1.6

Installation

Connection of external controls (CT3 only)

Vitocrossal 300 – operation with external modulation controller

1st stage burner fA from

Vitotronic 100.

Connection lÖ from Vitotronic has

no function.

Connection lÖ from building

automation system to the burner.

1st stage burner activated by the

modulation controller via connection
aVH.

(continued)

Boiler activation, isolation valve
open or closed

Connect dry contact at terminals
”2” and ”3” of the plug aVH.

Contact closed:
First, the preheat function for
follow-up boilers is activated
(coding address ”2b”).
When the preheat function finishes,
the burner stages/modulation can
be switched externally.
The boiler water temperature is
limited by the preset maximum
boiler water temperature or via the
mechanical adjustable high limit.
The setpoint value is selected via
the coding address ”9b”.

Contact open:
The isolation valve is closed after
approx. 5 minutes (coding address
”2C”).
External override of the burner
stages is not possible, and no
minimum temperature is maintained.

Switch on 1st stage burner (basic
load)

Connect dry contact at terminals
”1” and ”2” of the plug aVD.

Contact closed:
The 1st stage burner is switched on.
The boiler water temperature is
limited by the electronic maximum
temperature limit (coding address
”06”) if this is set below the value
preset on the mechanical adjustable
high limit ”R”.

Contact open:
The 1st stage burner is switched off.

5285 941 v.1.6

43

Installation

Connection of external controls (CT3 only)

Vitocrossal 300 – operation with external modulation controller (continued)

Settings on the control unit

The settings for the fixed high limit and
the other settings are dependent on the
safety equipment installed in
accordance with applicable codes.

Non-condensing boiler
(VD2/VD2A) °C / °F

Fixed high limit 110 / 230 99 / 210 99 / 210 99 / 210

Adjustable high limit 100 / 212 95 / 203 95 / 203 95 / 203

Coding for the electronic maximum
temperature limiter of Vitotronic 100;
set code 06 to the temperature as
shown or less

93 / 200 87 / 188 87 / 188 88 / 190

Single-boiler systems:

Coding ”01: 1”
(factory setting)

(continued)

Condensing boiler
(CT3) °C / °F

Condensing boiler
(CM2) °C / °F

Multi-boiler systems:

Set coding ”01: 3”

When a building automation system is
connected, only the connections on
plug aVD are required. The DHW tank
control unit is activated when the DHW
tank temperature sensor is connected.
The boiler water temperature must be
set to the minimum value.

When a building automation system
is connected, the connections on
plugs aVD and aVH are required.
The DHW tank temperature and the
load-dependent cascade control
must be controlled through the
building automation system.

CAUTION

The boiler activation contact is
essential on multi-boiler systems.
The contact on the lead boiler
MUST be constantly closed.

44

5285 941 v.1.6

Installation

Connections of combustion air device adaptor (VD2/VD2A/CT3 only)

Connection of the Combustion Air
Device Adaptor

1. Disconnect power to control and

burners.

2. Install Combustion Air Device
Adaptor, Part No.: 7134 563
on DIN Rail inside connection
enclosure (refer to installation
manual of Combustion Air
Device Adaptor).

3. Remove jumper between
terminals 16 and 17.

4. Make connection as shown in
the diagram.

IMPORTANT

Wire BK2 must be connected to
terminal 16 and BK3 to terminal
17 - DO NOT reverse.

D

A Combustion Air Device Adaptor
B DIN Rail in connection enclosure

Connection of the combustion air
blower to adaptor

Rated voltage: 120 VAC
Rating current: max 5 FLA
Recommended connection
wire size: AWG 14

Note:

Assure that combustion air blower
device is suitable for this application.

For detailed instruction on
adaptor installation, please refer
to the adaptor’s installation manual.

1. Make connection as shown in
the diagram at left.

A Combustion Air Device Adaptor

in connection enclosure

B Combustion air blower motor
C Proving switch - “normally open”

rated for 120 VAC

D Power supply, 120 VAC

5285 941 v.1.6

CAUTION

Provide disconnect means and
overcurrent protection as required
by local codes.

45

Installation

Connection of Combustion Air Device (CM2 only)

D

Connection of the Combustion Air
Device Adaptor

1. Disconnect power to control and
burners.

2. Install Combustion Air Device
Adaptor, Part No. 7134 563
on DIN Rail inside the boiler junction
box (refer to installation manual of
Combustion Air Device
Adaptor).

3. Remove plug 150 from Vitotronic
control. Remove jumper between
the 2 ’TR’ terminals. Using 14 AWG
(field supplied) connect plug
terminals TR(Left), TR(Right) and
neutral to the DIN rail.

Neutral to Terminal 16
TR(Left) to Terminal 18
TR(Right) to Terminal 19

Re-install the 150 plug and DIN rail
connections as shown in the diagram.

IMPORTANT

Connection of the combustion air
blower to adaptor

Rated voltage: 120 VAC
Rating current: max 5 FLA
Recommended connection
wire size: AWG 14

Ensure that combustion air blower
device is suitable for this application.

For detailed instruction on adaptor
installation please refer to the
adaptor’s installation manual.

1. Make connection as shown in the
diagram at left.

A Combustion Air Device Adaptor

in connection enclosure

B Combustion air blower motor
C Proving switch - “normally open”

rated for 120 VAC.

D Power supply, 120 VAC

¨ Safety instruction!

Provide disconnect means and
overcurrent protection as required
by local codes.

Wire BK2 must be connected to
terminal 18 and BK3 to terminal 19 ­DO NOT reverse.

46

5285 941 v1.6

Installation

Connection of combustion air device

(continued)

E

Connection of the combustion air
damper

See damper manual for correct
installation.

Note:

Assure that the combustion air
damper is suitable for this
application.

1. Disconnect power to control and
burner.

2. Make connection as shown in the
diagram.

A Combustion Air Device Adaptor

in connection enclosure

B Relay 120 VAC coil - field

supplied

C Combustion air damper
D End switch rated for 120 VAC

wired to “normally open”
terminal on device adaptor board

E Power supply, 120 VAC

CAUTION

Provide disconnect means and
overcurrent protection as required
by local codes.

Note:

Spring return air dampers do not
require field supplied relay.

5285 941 v.1.6

47

Installation

Flue Gas Temp. Switch (mandatory for PP(s) material collectors)

(CM2 only)

1. Disconnect power.

CAUTION

Please note that the diagram shown
is only a simplified conceptual
drawing of a flue gas temperature
switch. Refer to the manual specific
to the device for interconnection
details.

2. Remove 150 plug from the
Vitotronic control and discard.

3. Install new 150 plug supplied
(attached to flue gas temperature
switch).

48

5285 941 v1.6

Connection of low water cut-off device (VD2/VD2A/CT3 only)

1.Remove jumper between

terminals 12 and 15.

2.Make connection as shown in
diagram.

CAUTION

Please note that the diagram at
left is only a simplified conceptual
drawing of a typical low water
cut off (LWCO) device. Refer to
the manual specific to the device
for interconnection details.

Installation

aBH Power supply for accessories.

aBÖ Connection for external

equipment.

5285 941 v.1.6

49

Installation

Connection of Low Water Cut-off Device (CM2 only)

1. Remove jumper between terminals

21 and 22.

2. Make connection as shown in
diagram.

CAUTION

Please note that the diagram shown
is only a simplified conceptual
drawing of a typical low water
cut-off (LWCO) device. Refer to the
manual specific to the device for
interconnection details.

50

5285 941 v1.6

Burner connection, Burner control wiring (VD2/VD2A/CT3 only)

For burners with plug-in connection

Installation

A

41

120 VAC

B

The burner cables are included in the
standard delivery of the Vitotronic.

Connect the burner in accordance with
applicable codes.

ATo boiler control unit
BTo burner

Terminal codes

L1 Phase via fixed high limit to the

burner
? Ground connection
N Neutral connection to the burner
T1,T2 Control circuit
S3 Connection for burner fault

indicator
B4 Connection for burner hours

counter

1.Disconnect power to burner and
boiler control.

2. Connect plugs fA and plug lÖ to
respective counter plugs in boiler
control unit.

3. Connect the 7-pole plug fA and
the 3-pole plug lÖ to the burner.

Terminal codes

A To plug-in connection in connection

enclosure

B To burner

5285 941 v.1.6

1,2,3 Control circuit ”2nd stage

burner or modulation controller”
(via two-point controller with
2-stage operation; via three­point controller with modulating

operation)
1 From burner
2 Modulating down
3 Modulating up/2nd stage ON

Colour codes as applicable

BK Black
BN Brown
BU Blue

51

Installation

Burner Connection, Burner Control Wiring (VD2/VD2A/CT3 only)

CAUTION

This is a generic connection drawing
only! Follow the burner
manufacturer’s connection drawings
for Viessmann controls.

Write the terminal numbers or
markings on the drawing for future
reference.

(continued)

a b

A Control unit

(Legend: see wiring diagram)

B 2nd stage or modulating *
C Hours counter, stage 1 *
D Burner fault indicator *
E Control circuit, stage 1/

basic load *

F Burner

1

1

Plug connection
located on the
DIN rail.

Burner power supply not shown.

fÖ Power supply connection of control

1

1

unit 120 VAC

fA Burner, 1st stage
lÖ Burner, 2nd stage

aBÖ Plugs for external equipment

a External safety devices
(remove jumper when connecting)
b External controlled switch-off
(remove jumper when connecting)

aBA Safety circuit. Emergency

shut-off

*1Refer to burner manufacturer’s instruction on detailed connections for Viessmann controls.

52

5285 941 v1.6

Installation

Burner Connection, Burner Control Wiring (VD2/VD2A/CT3 only)

Burner motor power supply connection

(continued)

See burner manual for correct fuse

For burners with 240 VAC, 1PH power
supply and connection in conduit.

and wire gauge sizing, and specific
connections for Viessmann controls.

1.Disconnect power to burner and

boiler control.

2.Connect 240 VAC power to the

terminals 21, 22 and 23 on the
DIN rail inside the connection
enclosure. Provide fuseable
disconnect means according to
local codes.

3.Connect supplied power cable to

the motor terminals on the burner.

4.Connect cable plug to the socket

on the DIN rail in the connection
enclosure.

(continued)

A Burner motor power supply

240 VAC, 1PH

B Connection terminals and plug

inside connection enclosure

C Cable and conduit- factory supplied
D Burner
E Motor starter
F Burner motor
G Connection enclosure on boiler

control

5285 941 v1.6

53

Installation

Burner Connection, Burner Control Wiring (VD2/VD2A/CT3 only)

Burner motor power supply connection

(continued)

For burners with 3PH 208, 460 or
575V power supply.

See burner manual for correct fuse
and wire gauge sizing, and specific
connections for Viessmann controls.

1.Disconnect power to burner and
boiler control.

2.Connect 3PH power to the
terminals 21, 22, 23 and 24 on
the DIN rail inside the connection
enclosure. Provide fuseable
disconnect means according to
local codes.

3.Connect supplied power cable to
the motor terminals on the burner.

4.Connect cable plug to the socket
on the DIN rail in the connection
enclosure.

(continued)

A Burner motor power supply 3PH

208, 460 or 575V

B Connection terminals and plug

inside connection enclosure

C Cable and conduit - factory

supplied

D Burner
E Motor starter
F Overload
G Burner motor
H Connection enclosure

CAUTION

During commissioning check for
correct motor rotation. If motor
rotates in opposite direction than
indicated on the burner, disconnect
power supply and reverse wires BK1
and BK2 on the burner terminals.

54

5285 941 v1.6

Power Supply Connection, Boiler Control (VD2/VD2A/CT3 only)

Installation

Legend

L: Line
N: Neutral
G: Ground
A Power supply 120 VAC, 1 PH .

Provide disconnect means and
overcurrent protection as per local

codes

B Terminals [40]
C Connection enclosure

1. Ensure that the main power supply
to the control contains overcurrent
protection with a maximum rating
of 15 A and 2 pole disconnect.

CAUTION

The control must be grounded.
Ensure that “L”, “N” and “G” are not
interchanged.

2. Connect power supply wire to the

Connection fÖ terminals 11, N and
G on the DIN rail inside the
connection enclosure.

5285 941 v1.6

55

Installation

Burner Connection, Burner Control Wiring (CM2 only)

For burners with plug-in connection

A

B

The burner cables are included in the
standard delivery of the Vitotronic.

Connect the burner in accordance with
applicable codes.

ATo boiler control unit
BTo burner interface

Terminal codes

L1 Phase via fixed high limit to the

burner
? Ground connection
N Neutral connection to the burner
T1,T2 Control circuit
S3 Connection for burner fault

indicator
B4 Connection for burner hours

counter

1.Disconnect power to burner and
boiler control.

2. Connect plugs fA and plug lÖ to
respective counter plugs in boiler
control unit.

3. Connect the 7-pole plug fA and
the 3-pole plug lÖ to the burner.

A

B

A To plug-in connection in connection

enclosure

B To burner interface

Terminal codes

1,2,3 Control circuit ”2nd stage

burner or modulation controller”
(via two-point controller with
2-stage operation;
via three-point controller with

modulating operation)
1 From burner
2 Modulating down
3 Modulating up/2nd stage ON

Colour codes as applicable

BK Black
BN Brown
BU Blue

5285 941 v1.6

56

Mounting the Front Part of the Control Unit (VD2/VD2A/CT3 only)

1.

8.

1. Position the front part of the housing
and clip hinges to counter-parts on
main housing.

Installation

7.

2. Release the stay bar, open it up
and lock in position at point A.

3. Insert the flat cable from the
Optolink into plug ”X20”.

4. Insert the plug of the programming
unit into socket ”X10”. Use cable
guides in cover for routing.

5. Engage the stay bar in the front
housing.

6. Close the front of the housing.

7. Secure front housing with supplied

screws.

8. Install cover of the connection
enclosure and support with supplied
screw.

2.

6.

A

5.

4.

3.

5285 941 v1.6

57

Installation

Mounting the Front Part of the Control Unit (VD2/VD2A/CT3 only)

1.

8.

1. Position the front part of the housing
and clip hinges to counter-parts on
main housing.

7.

2. Release the stay bar, open it up
and lock in position at point A.

3. Insert the flat cable from the
Optolink into plug ”X20”.

4. Insert the plug of the programming
unit into socket ”X10”. Use cable
guides in cover for routing.

5. Engage the stay bar in the front
housing.

6. Close the front of the housing.

7. Secure front housing with supplied

screws.

8. Install cover of the connection
enclosure and support with supplied
screw.

2.

6.

A

5.

4.

3.

58

5285 941 v1.6

Opening the Control Unit (VD2/VD2A/CT3 only)

Installation

1. Remove the cover of the
connection enclosure.

1.

2.

2. Unscrew the screws from the
front housing.

3. Swing up the front part of the
control housing.

4. Position the stay bar so that it
supports the front housing.

4.

3.

5285 941 v1.6

59

Installation

Control and Junction Box Installation Instructions (for CM2 only)

1. Route cables and capillaries from
control through the opening in the
control panel. Guide the cables to
the junction box through the
opening in the rear panel and along
the top rail to the control. Secure
all cables to the rail with cable ties.
Insert capillaries into the sensor well.
Note: Never allow cables to come

in contact with hot metal
components.

WARNING

Do not bend or kink the capillaries.
Damaging the capillaries leads to
malfunction.

2. Mount the control to the control
panel.

3. Secure the control to the control
panel with screws.
Note: Screws to secure control are

included with the cosmetic
cover in the boiler jacketing
package.

4. Install the junction box to the rear
panel either right or left. Secure the
junction box with 4 x 4.8 metal
screws.

Note:The ground screw and ground

wire can be removed and then
reinstalled with the boiler back
panel attached.

60

5285 941 v1.6

Mounting the Front Part of the Control Unit (CM2 only)

1. Position the front part of the housing

and clip hinges to counter-parts on
main housing.

Installation

2. Release the stay bar, open it up

and lock in position at point A.

3. Insert the flat cable from the
Optolink into plug ”X20”.

4. Insert the plug of the programming
unit into socket ”X10”. Use cable
guides in cover for routing.

5. Engage the stay bar in the front
housing.

6. Close the front of the housing.

7. Secure front housing with supplied

screws.

8. Install control cosmetic cover.

A

5285 941 v1.6

61

Installation

Opening the Control Unit (CM2 only)

1. Remove the control cosmetic

cover .

2. Unscrew the screws from the
front housing.

3. Swing up the front part of the
control housing.

4. Position the stay bar so that it
supports the front housing.

62

5285 941 v1.6

Procedure (overview)

Start-up

Page

11. Controls and indicators 64

12. Check assignment of heating circuits 64

13. Check the fixed high limit 65

14. Select the language (if required) 65

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

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

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

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

15. Integrate the control unit in the LON BUS system

(in conjunction with heating circuits connected
downstream) 66

16. Carry out participant check 67

17. Match the control unit to the system type 68

18. Check outputs (actuators) and sensors 68

19. Match the coding addresses 69

10. Adjust the heating curves 71

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

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

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

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

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

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

5285 941 v.1.6

63

Start-up

Steps

1. Controls and indicators

Kesseltemperatur

Mo

Override switch

Heating circuit selection

Display window

Normal room temperature

Heating programs

Adjustable high limit

Fixed high limit reset button

2. Check assignment of heating circuits

Boiler temperature

Mo

61

Control on/off switch

Fuses

TÜV TEST button

Energy saving mode

Party mode

Hinged cover of programming unit

Operating status indicator (green)

Fault indicator (red)

Check that the stickers for the assignment of the heating circuits are affixed in
the appropriate locations on the control unit.
The corresponding button must be pressed before commencing each setting.

64

5285 941 v.1.6

Start-up

Steps

3. Check the fixed high limit

(continued)

The check is made via the ”TÜV TEST” button (see page 64).

When making the check, the ” TÜV
TEST” button must be kept
continuously pressed.
A minimum supply is required
during the check.
The minimum amount of recirculated
water should be 10% of the amount
recirculated at the rated load.
The amount of heat consumed
should be reduced as far as possible.
The adjustable high limit ”R” is
bridged. The burner is switched on
until the boiler water temperature
reaches the safety temperature and
the fixed high limit operates.
When the burner is switched off by
the fixed high limit, release the
”TÜV TEST” button, wait until the
boiler water temperature has fallen 15
to 20°C / 27 to 36°F below the
selected safety temperature and
then reset the fixed high limit by
pressing the ”E” button.

4. Select the language (if required)

Outdoor temp erature

12

5285 941 v.1.6

1. Press .

2. Select the required language with

.

3. Confirm with .

The outdoor temperature or the
participant number is displayed.

65

Start-up

Steps

5. Integrate the control unit in the LON BUS system in conjunction with Vitotronic 200-H

(continued)

User check

The LON communication module (accessory) must be inserted (see page 96).

Set the LON participant number

Set the LON participant number via
coding address ”77” in coding 1
(factory setting: ”77: 1”).

Update the LON participant list

This is only possible when all participants are connected and the control unit is
coded as the fault manager (coding ”79: 1”).

1. Press w and simultaneously for
approx. 2 seconds.

2. Press D.

See page 114 for coding 1.

Please note:

The same number must not be
assigned twice within a LON BUS
system.

The participant check is initiated.

The participant list is updated
after approx. 2 minutes.
The participant check is
terminated.

Example of single-boiler system with Vitotronic 200-H heating circuit controls and Vitocom 300 connected downstream

Vitotronic 300 Vitotronic 200-H Vitotronic 200-H Vitocom

LON LON LON

Participant No. 1
Coding ”77: 1”

Control unit is fault manager
Coding ”79: 1”

Transmit time via LON
Set coding ”7b: 1”

Transmit outdoor
temperature via LON
Coding ”97: 2”

Viessmann system number
Coding “98: 1”

Fault monitoring
LON-Participant
Coding “9C: 20”

Participant No. 10
Coding ”77: 10”

Control unit is not fault
manager
Coding ”79: 0”

Time is received via LON
Set coding ”81: 3”

Outdoor temperature is
received via LON
Set coding ”97: 1”

Viessmann system number
Coding “98: 1”

Fault monitoring
LON-Participant
Coding “9C: 20”

Participant No. 11
Coding ”77: 11”

Control unit is not fault
manager
Coding ”79: 0”

Time is received via LON
Set coding ”81: 3”

Outdoor temperature is
received via LON
Set coding ”97: 1”

Viessmann system number
Coding “98: 1”

Fault monitoring
LON-Participant
Coding “9C: 20”

Participant No. 99

Unit is fault manager

Time is received via LON

66

5285 941 v.1.6

Start-up

Steps

6. Carry out participant check

(continued)

User check

Participant check

The participant check is used to verify the communication of the system units
connected to the fault manager.
Requirements:

The control unit must be coded as the fault manager (coding ”79: 1”)
The LON participant number must be coded in all control units
The participant list must be updated in the fault manager

1. Press w and simultaneously
for approx. 2 seconds.

The participant check is initiated.

01 : 01

1

Anlagenschema

Cod. 1

Participant number
Consecutive list number

2. Select the required participant
with or .

3. Activate the check with .
If communication between the two
units is verified, ”Check OK”
appears in the display.
If communication is not verified,

”Check not OK” appears.

4. To check further participants,

follow the steps described in
points 2 and 3.

5. Press w and simultaneously
for approx. 2 seconds.

”Check” flashes until the check
is completed.
The display of the selected
participant flashes for approx.
60 seconds.

Check the LON connection.

The participant check is
terminated.

5285 941 v.1.6

67

Start-up

Steps

7. Match the control unit to the system type

8. Check outputs (actuators) and sensors

(continued)

Relay test

Set the following coding addresses in
Coding 2:
”00” System type
”02” Burner type
”03” Oil or gas-fired operation
”0C” Return temperature raising
”4C” Plug sÖ function
”4d” Plug sL function
”4E” Plug gS function

Carry out relay test

1. Press and simultaneously for

2. Select relay outputs with the or

See page 116 for coding 2.

Relay test is activated.

approx. 2 seconds.

button.

3. Press .

The following relay outputs can be
selected depending on the system
equipment installed:

Burner stage 1 ON

Burner stage 1 + 2 ON

Burner modulation open

Burner modulation neutral

Burner modulation closed

Output 20 ON

Output 29 ON

Output 52 open/closed/neutral

DHW tank pump ON

DHW circulation pump ON

Heating circuit pump (M2) ON

Relay test is terminated.

Mixing valve (M3) Closed

Central fault indicator ON

LED selector button ! illuminated.

LED selector button ! illuminated.

LED selector button ! illuminated.

LED selector button ? illuminated.

LED selector button § illuminated.

LED selector button ? illuminated.

68

Heating circuit pump (M3) ON

Mixing valve (M2) Open

Mixing valve (M2) Closed

Mixing valve (M3) Open

LED selector button ? illuminated.

LED selector button § illuminated.

LED selector button § illuminated.

All LEDs extinguished.

5285 941 v.1.6

Start-up

Steps

(continued)

Relaistest

9. Match the coding addresses

Check sensors

1. Press .

Scanning of operating status
information is activated

2. Scan actual temperatures with

(see page 77).

or .

3. Press .

Scanning is terminated.

Match control unit to modulating burner

Please note:

The burner must be adjusted. In order to achieve a wide modulation range, the
minimum output should be set as low as possible (take chimney/flue system
into account).

1. Start up the burner.

Burner mod. open

Burnermod. closed

Burner mod. open

2. Press and simultaneously
for approx. 2 seconds.

3. With function
Activate ”Burner mod. open” and
wait until the actuating drive of the
burner is at maximum output.

4. Establish the maximum burner
out-put through the fuel
consumption.

5. With function
Activate ”Burner mod. closed” and
measure the time it takes for the
actuating drive of the burner to
reach the minimum output.

6. Establish the minimum burner
output (basic output) through the
fuel consumption.

7. With function
Activate ”Burner mod. open” and
stop the actuating drive by pressing

after one-third of the time

measured in point 5.

The relay test is activated.

Make a note of the value.

Make a note of the value.

Make a note of the value.

5285 941 v.1.6

8. Establish the partial output through
the fuel consumption.

9. Press .

Make a note of the value.

The relay test is terminated.

69

Start-up

Steps

9. Match the coding addresses (continued)

(continued)

Address Setting of

05 the partial output (see point 8) as a percentage proportion of the

08 units and tens digits of the maximum output established in point

09 hundreds digit of the maximum output established in point 4: e.g.

0A the basic output (see point 6) as a percentage proportion of the

15 the operating time in seconds established in point 5

10. Set the established values in coding
Level 1.

max. output; e.g.
partial output: 170 kW
max. output: 210 kW

170 kW
210 kW

4: e.g. max. output: 210 kW – here set: 10

max. output: 210 kW – here set: 2

max. output; e.g.
basic output: 70 kW
max. output: 210 kW

70 kW

210 kW

x100 % = 81 %

x100 % = 33 %

See page 114 for coding 1.

Please note:

You will find details of other possible settings in the sections entitled
”Coding 1” and ”Coding 2” (see page 114 and 116).

70

5285 941 v.1.6

Start-up

Steps

(continued)

10. Adjust the heating curves

The heating curves represent the relationship between the outdoor temperature
and the boiler water or supply temperature. Put simply: The lower the outdoor
temperature, the higher the boiler water temperature. In turn, the room
temperature is dependent on the boiler water temperature.

Slope

The slope of the heating curve is
normally within the range marked

3.4

3.2

3.0

2.8

2.6

2.4

A for underfloor heating systems
B for modulating heating systems

2.2

2.0

1.8

1.6

1.4

1.2

C for heating systems with boiler

water temperatures over 75°C.

Factory settings:

Slope ”n” = 1.4
Shift ”N”= 0

See conversion chart on the back
of the manual for °F.

1.0

0.8

0.6

Boiler water

= flow temperature in °C

0.4

0.2

Outdoor temperature in °C

1. Set the desired room temperature

Desired room temperatures can
be set separately for each heating
circuit.

Normal room
temperature

Reduced room
temperature

Normal room temperature

Set the desired day temperature with

20

the set-point selector.

Reduced room temperature

14

Press tm to call up the desired night
temperature; adjust the desired night

The value is automatically
accepted after approx. 2 seconds.

temperature with the or
button.

5285 941 v.1.6

Press to confirm the selected
value.

The display changes and shows
the boiler water temperature.

71

Scanning service information

Press“OK”and“+”or

Overview of service levels

Function Button combination To exit Page

Temperatures, boiler coding cards
and scans

Relay test Press 9 and “OK” simultaneously

Participant check (in conjunction
with LON)

Operating status information Press 

Service scan  (if ”Service” flashing)

Adjustment of display contrast

Press 9 and rw simultaneously
for approx. 2 seconds

for approx. 2 seconds

Press w and “OK” simultaneously
for approx. 2 seconds

Press “OK” and “+” or

“OK” and “-” simultaneously

Press “OK”

Press “OK”

Press w and “OK” simultaneously
for approx. 1 second

Press 

Press “OK”

Display darkens
Display brightens

73

68

66

77

74

––
––

72

5285 941 v.1.6

Temperatures, boiler coding cards and scans

Scanning service information

Outdoortemp.damped

-5

1. Press 9 and rw simultaneously
for approx. 2 seconds.

2. Select the required data for scanning
with the or button.

3. Press . Exit diagnosis level.

The following values can be scanned
depending on the system equipment
installed:

Damped outdoor temp.
Current outdoor temp.

Output reduction %
Desired boiler temp.
Current boiler temp.

Sensor 17A, current value

Sensor 17B, current value

Max. flue gas temp.
Current flue gas temp.

Access diagnosis level.

The damped outdoor temperature
can be reset to the current
outdoor temperature by pressing D.

Only displayed if sensor
connected.
Only displayed if sensor
connected.

Only displayed if flue gas
temperature sensor connected.
The max. flue gas temperature
can be reset to the current value
by pressing D.

Desired DHW temp.
Current DHW temp.
Current DHW temp. 1
Current DHW temp. 2

Desired supply temp.
Current supply temp.

Desired room temp.
Current room temp.

Boiler coding card

Scan 1
Scan 2
Scan 3
Scan 4
Scan 5

Scan 6

Scan 7

Only displayed if DHW tank
temperature sensor connected.
Only displayed if two DHW tank
temperature sensors are connected.

Only displayed if supply
temperature sensor connected.

Only displayed if remote control
connected.

See overview of boiler coding
cards on page 94.

See page 74 for scans 1 to 7.

Only in conjunction with LON
communication module
Only in conjunction with LON
communication module

5285 941 v.1.6

73

Scanning service information

Temperatures, boiler coding cards and scans

Scan 1

Scan 1

8

KM BUS participant

0

No participant connected

1

to

Number of participants

F

(e.g. remote control)

Burner type Coding

Single-stage 02: 0

0
1

2-stage 02: 1

2

Modulating 02: 2

88888

Free

Free

(continued)

System type
System circuit A1 Mixing valve Mixing valve DHW Coding

circuit M2 circuit M3 tank

0 1 Yes 00: 11
0 2 Yes Yes 00: 12
0 3 Yes 00: 13
0 4 Yes Yes 00: 14
0 5 Yes Yes 00: 15
0 6 Yes Yes Yes 00: 16
0 7 Yes Yes 00: 17
0 8 Yes Yes Yes 00: 18
0 9 Yes Yes Yes 00: 19
1 0 Yes Yes Yes Yes 00: 10

74

5285 941 v.1.6

Scanning service information

Temperatures, boiler coding cards and scans

Scan 2

Scan 2

88888

Software version

0

Plug-in adaptor for external safety equipment

to

F

Software version
Extension kit for mixing valve circuit M3

0

to

0

to

F

F

Software version
Control unit

8

0

to

F

Free

0

Software version

to

Extension kit for mixing valve circuit M2

F

Software version
Programming unit of control unit

(continued)

Scan 3

Scan 3

0
1

5285 941 v.1.6

2

8

0
1

0

to

F

Operating mode of mixing valve circuit M2 Coding

Without remote control A0: 0

0
1

With Vitotrol 200 remote control A0: 1

2

0

to

Software version

F

Remote control for system circuit A1

Operating mode of system circuit A1 Coding

Without remote control A0: 0
With Vitotrol 200 remote control A0: 1
With Vitotrol 300 remote control A0: 2

With Vitotrol 300 remote control A0: 2

2

Software version
Remote control for mixing valve circuit M2

88888

0

to

Software version

F

Remote control for mixing valve circuit M3

Operating mode of mixing valve circuit M3 Coding

Without remote control A0: 0
With Vitotrol 200 remote control A0: 1
With Vitotrol 300 remote control A0: 2

75

Scanning service information

Scan5

Temperatures, boiler coding cards and scans

Scan 4

Scan 4 is not assigned.

Scan 5 only in conjunction with LON communication module

8

0

0

0

to

F

Scan 6 only in conjunction with LON communication module

0

to

F

to

F

Viessmann participant number

0

to

F

to

F

Subnet address/system number

88888

0

to

Node address

F

(continued)

Scan 6

0

to

Tool/Auto

F

SNVT configuration

Scan 7

Scan 7

8

0

to

0

to

F

F

Software version
Communication coprocessor

0

Software version

to

F

Neuron chip

8

to

88888

LON participant

0
1

F

0

No participant connected

1

to

Number of participants

F

88888

0

to

F

76

0

to

Equipment identification code

F

Free

Free

Free

Free

5285 941 v.1.6

Scanning operating status information

Scanning service information

Outdoor temp erature

12

1. Press .

2. Select the required operating status

data for scanning with the or
button.

3. Press .

The following operating status
information can be scanned depending
on the system equipment installed:

Participant number

Holiday program

with date of departure and return

Holiday program active
Outdoor temperature
Boiler temperature
Flue gas temperature

Sensor 17A
Sensor 17B
DHW temperature

DHW temperature 1
DHW temperature 2
Supply temperature

Burner hours run

– 1st stage burner
– 2nd stage burner

Number of burner starts

Fuel consumption

Operating status scanning mode
is activated.

Exit the operating status scanning
mode.

Only displayed when LON
communication module is installed.
If holiday program has been
entered.
When the holiday program is
activated.

Only displayed if flue gas
temperature sensor is connected.
Only displayed if sensor is
connected.
Only displayed if DHW tank
temperature sensor is connected.
Only displayed if two DHW tank
temperature sensors are connected.
Only displayed in conjunction with
mixing valve circuits.
Reset hours runs, number of
burner starts and fuel consumption
after carrying out maintenance.
By pressing D, the values can be
individually reset to zero.
Only displayed if selected via
coding addresses ”26” or ”29”.

5285 941 v.1.6

Time
Date
1st stage burner ON/OFF
2nd stage burner ON/OFF
Output 20 ON/OFF
Output 29 ON/OFF
Output 52 Open/Closed
DHW tank pump ON/OFF
DHW pump ON/OFF
Heating circuit pump ON/OFF
Mixing valve Open/Closed
Different languages

Position stated in %.

Position stated in %.
Press to select the respective
language as the permanent
language for all displays.

77

Scanning service information

Scanning and resetting the ”Service” display

When the limit values selected via coding addresses ”1F”, ”21” and ”23” (see
page 120) are reached, the ”Service” display flashes on the programming unit.

Please note:

If a service is carried out before ”Service” is displayed, set the coding address
”24: 1” and then coding address ”24: 0”.

Service

MFlue gas temperature

220

Boiler temperature

61

°C

Press . Service scan is activated.

Scan the service messages with the

or button.

Press and confirm the display
”Acknowledge: Yes” by pressing

.

Press . Service scan is terminated.

The ”Service” display is
extinguished.

Please note:

An acknowledged service
message can be displayed again
by pressing (for approx.
3 seconds).

78

After carrying out maintenance,
reset coding ”24: 1” (see page 120)
to ”24: 0”.

If necessary: After carrying out
maintenance

Press .
Reset burner hours run, number

of burner starts and fuel
consumption.

Press .

If necessary: After carrying out
maintenance
Press and rw simultaneously

for approx. 4 seconds.

Reset ”Max. flue gas temp.” to

the current value by pressing D.

Press .

If coding address ”24” is not
reset, the ”Service” display will
re-appear at 07:00 hrs on Monday.

See ”Scanning operating status
information” on page 77.

See ”Temperatures, boiler coding
cards and scans” on page 74.

5285 941 v.1.6

Troubleshooting steps

Troubleshooting

Diagnosis 1. Establish fault message or ascertain behaviour of system

2. Look for the corresponding cause of the fault in the
diagnosis tables

Please note:

Retrieve fault codes from the fault memory

3. Establish the action required in the table

Correction 4. Correct the fault

5285 941 v.1.6

79

Troubleshooting

Diagnosis

Faults with fault display on the programming unit

Fault

57

Fr

Fault

Mo

1

w A

57

ºC

Outdoor sensor

DBG-

1

101

Fault

DBG-

1

672

Acknowledge? Yes

1

Outdoor sensor

DBG-

1

101

When a fault message is transmitted,

--Fault-- flashes in the display 1 of the
programming unit.

Search fault

1. Press .

2. Other fault codes which may be

stored can be called up by pressing
the or button.

Structure of fault display

Fault display
(”Plain language” or ”Fault”)
Fault code
(meaning: see page 70)
Fault number
(1 to 10)
Fault symbol

The meaning of the fault code is
explained in the table on page 81
onwards.

The fault can be acknowledged
by pressing . The fault message
in the display 1 is blanked out;
the red fault indicator 2 continues
to flash.
The central fault indicator
connected to plug gÖ is switched
off. If an acknowledged fault is not
rectified by 07:00 hrs on the
following day, the fault message
will re-appear in the display.

To retrieve an acknowledged fault
message

Press for approx. 3 seconds; select
the acknowledged fault by pressing the

or button.

The fault is then displayed

Please note:

The red fault indicator 2 flashes
whenever there is a fault.

80

Faults displayed in plain language

Burner
Fixed high limit
Safety circuit, potential free
Ext. fault
Outdoor sensor
Supply sensor
Boiler sensor
DHW tank temperature sensor 1

(or 2)

Sensor 17A
Sensor 17B
Room sensor
Flue gas sensor
Participant fault

C1, C8, C9, CA, Cb
Meaning: see table on page 84.

Only displayed if a second DHW
tank temperature sensor is
connected.

Only displayed if the control unit is
coded as the fault manager.

5285 941 v.1.6

Troubleshooting

Faultcode

Diagnosis

Faults with fault display on the programming unit (continued)

in display

0f

10

18

30

38

40

44

48

4c

50

51

58

59

5285 941 v.1.6

(continued)

Behaviour of system

Controlled operation Service required

Operates on basis of 0°C outdoor
temperature

Operates on basis of 0°C outdoor
temperature

Burner is switched on and off by the
adjustable high limit

Burner is switched on and off by the
adjustable high limit

Mixing valve is closed Short circuit

Mixing valve is closed Short circuit

Mixing valve is closed Open circuit

Mixing valve is closed Open circuit

DHW tank heating pump ON:
Desired boiler temperature = desired
DHW tank temperature, priority controls
are cancelled.
In conjunction with DHW tank heating
system:
DHW tank heating is switched on and off
by DHW tank temperature sensor 2.

In conjunction with DHW tank loading
system:
DHW tank heating is switched on and off
by DHW tank temperature sensor 1.

DHW tank loading pump ON:
Desired boiler temperature = desired
DHW tank temperature, priority controls
are cancelled.
In conjunction with DHW tank loading
system:
DHW tank heating is switched on and off
by DHW tank temperature sensor 2.

In conjunction with DHW tank loading
system:
DHW tank heating is switched on and off
by DHW tank temperature sensor 1.

Cause of fault Action

Carry out maintenance
”0F” is only displayed
in the fault history

Short circuit
Outdoor temperature sensor

Open circuit
Outdoor temperature sensor

Short circuit
Boiler temperature sensor

Open circuit
Boiler temperature sensor

Supply temperature sensor of
mixing valve circuit M2

Supply temperature sensor of
mixing valve circuit M3

Supply temperature sensor of
mixing valve circuit M2

Supply temperature sensor of
mixing valve circuit M3

Short circuit
DHW tank temperature
sensor 1

Short circuit
DHW tank temperature sensor
2

Open circuit
DHW tank temperature sensor
1

Open circuit
DHW tank temperature sensor
2

Please note:

After carrying out main-

tenance, set coding ”24: 0”.

Check outdoor temperature

sensor (see page 99)

Check outdoor temperature

sensor (see page 99)

Check boiler temperature

sensor (see page 101)

Check boiler temperature

sensor (see page 101)

Check supply temperature

sensor (see page 28)

Check supply temperature

sensor (see page 86)

Check supply temperature

sensor (see page 86)

Check supply temperature

sensor (see page 86)

Check DHW tank

temperature sensor

(see page 101)

Check DHW tank

temperature sensor

(see page 101)

Check DHW tank

temperature sensor (see

page 101)

Check DHW tank

temperature sensor (see

page 101)

81

Troubleshooting

Faultcode

Diagnosis

Faults with fault display on the programming unit (continued)

in display

60

68

70

78

92

93

94

9a

9b

9c

9f

(continued)

Behaviour of system

Boiler with maximum temperature
No output reduction
Return control open

Boiler with maximum temperature
No output reduction
Return control open

Shunt pump ON continuously Short circuit

In conjunction with DHW tank
loading system:
Mixing valve of primary circuit
closed.
No domestic hot water heating

Shunt pump ON continuously

In conjunction with DHW tank
loading system:
Mixing valve of primary circuit
closed.
No domestic hot water heating

Controlled operation
Only the solar control fault codes are
displayed

Controlled operation
Only the solar control fault codes are
displayed

Controlled operation
Only the solar control fault codes are
displayed

Controlled operation
Only the solar control fault codes are
displayed

Controlled operation
Only the solar control fault codes are
displayed

Controlled operation
Only the solar control fault codes are
displayed

Controlled operation
Only the solar control fault codes are
displayed

Cause of fault Action

Short circuit
Temperature sensor aJA

Open circuit
Temperature sensor aJA

Temperature sensor aJB

Open circuit
Temperature sensor aJB

Short circuit
Collector temperature sensor S1
on the Vitosolic

Short circuit
Temperature sensor S3 on the
Vitosolic

Short circuit
Collector temperature sensor S2
on the Vitosolic

Open circuit
Collector temperature sensor S1
on the Vitosolic

Open circuit
Temperature sensor S3 on the
Vitosolic

Open circuit
DHW tank temperature sensor S2
on the Vitosolic

Fault on solar control message
will display if no fault code is
assigned to the fault

Check temperature sensor
(see page 102)

Check temperature sensor
(see page 102)

Check temperature sensor
(see page 102)

Check temperature sensor
(see page 102)

Check sensor on the solar
control

Check sensor on the solar
control

Check sensor on the solar
control

Check sensor on the solar
control

Check sensor on the solar
control

Check sensor on the solar
control

Check the solar control

82

5285 941 v.1.6

Troubleshooting

Faultcode

Diagnosis

Faults with fault display on the programming unit (continued)

in display

aa

ab

ac

b0

b1

b4

(continued)

Behaviour of system

Controlled operation Therm-Control configuration

Controlled operation,
DHW tank may be cold

Controlled operation Return temperature raising

Controlled operation Short circuit

Controlled operation Communication fault

Emissions test mode Internal fault Check electronics board

Cause of fault Action

fault: plug aJA of
Therm-Control temperature
sensor not inserted

DHW tank loading system
configuration fault: coding ”55: 3” is
set, but plug aJB is not inserted and/
or coding ”4C: 1” and ”4E: 1” not set

configuration fault: coding ”0C: 1” is
set, but plug aJA is not inserted
and/or coding ”4E: 0” is not set

Flue gas temperature sensor

Programming unit

Insert plug aJA
On Vitocrossal:
Check that coding ”0d: 0”
is set.

Insert plug aJB and check
codings

Insert plug aJA and check
codings

Check flue gas temperature
sensor (see page 29)

Check connections, if
necessary replace
programming unit

b5
b6

b7

b8
ba

bc

bd

be

bf

Controlled operation Internal fault Check electronics board

Operation at constant
temperature

Boiler controlled on basis of
adjustable high limit

Controlled operation Open circuit

Mixing valve continues in control
mode

Controlled operation without
remote control

Controlled operation without
remote control

Controlled operation without
remote control

Controlled operation Incorrect LON communication module Replace communication

Invalid hardware code

Internal fault
Boiler coding card

Flue gas temperature sensor
Communication fault

Circuit board for mixing valve
extension

Communication fault
Vitotrol remote control,
system circuit A1

Communication fault
Vitotrol remote control,
mixing valve circuit M2

Communication fault
Vitotrol remote control,
mixing valve circuit M3

Check the control software
circuit board and confirm the
coding address:

- Enter coding 2 (see page 125
for instructions).

- Change code 8A to 176.

- Confirm coding 92:1

Insert boiler coding card or
replace if defective
(see page 22)

Check flue gas temperature
sensor (see page 104)

Check circuit board

Check connections, cable and
coding address ”A0”
(see Coding 2 page 127)

Check connections, cable and
coding address ”A0”
see Coding 2 page 127

Check connections, cable and
coding address ”A0”
see Coding 2 page 127

module

65

5285 941 v.1.6

83

Troubleshooting

Faultcode

toDE3

Diagnosis

Faults with fault display on the programming unit (continued)

in display

c1

c2

c4

c8

c9

ca

cb

cd

cEe

cf

d1

(continued)

Behaviour of system

Boiler cools down External safety equipment Check connection of plug

Controlled operation Open circuit

Controlled operation Fault

Boiler cools down Fault

Boiler cools down Fault

Boiler cools down Fault

Boiler cools down Fault

Controlled operation Communication fault

Controlled operation Communication fault

Controlled operation Fault

Boiler cools down Burner fault Check burner

Cause of fault Action

KM-BUS to solar control

Input module 0-10V

Low water indicator

Maximum pressure limiter

Minimum pressure limiter or
maximum pressure limiter 2

Additional fixed high limit

Vitocom 300

Plug-in adaptor for external safety
equipment

LON communication module

aBÖ

Check external safety

equipment (see page 40)

Check KM-BUS connection and
solar control. Without solar
control, set coding address
“54: 0”

Check all connections, cables etc.
Replace function expansion
module; without expansion
module set coding address
“9d: 0”

Check water level of system,
reset low water indicator

Check system pressure, reset
maximum pressure limiter

Check system pressure, reset
minimum or maximum pressure
limiter

Check system pressure, reset
fixed high limit, reset flue gas
damper

Check connections and
Vitocom 300

Check plug-in adaptor for
external safety equipment

Replace communication module

d4
d6

d7

d8

da

db

84

Boiler cools down Fixed high limit has operated Check fixed high limit

Controlled operation Fault at DE1 in the plug-in

Controlled operation Fault at DE2 in the plug-in

Controlled operation Fault at DE3 in the plug-in

Controlled operation without
influence of room
temperature

Controlled operation without
influence of room
temperature

adaptor for external safety equipment

adaptor for external safety equipment

adaptor for external safety equipment
Short circuit

Room temperature sensor, system
circuit A1

Short circuit
Room temperature sensor,
mixing valve circuit M2

Check connection at inputs DE1
to DE3

Check room temperature sensor
(see page 112)

Check room temperature sensor
(see page 112)

5285 941 v.1.6

Troubleshooting

Faultcode

Diagnosis

Faults with fault display on the programming unit (continued)

in display

dc

dd

de

df

e0

(continued)

Behaviour of system

Controlled operation without
influence of room temperature

Controlled operation without
influence of room temperature

Controlled operation without
influence of room temperature

Controlled operation without
influence of room temperature

Controlled operation Open circuit

Cause of fault Action

Short circuit
Room temperature sensor,
mixing valve circuit M3

Open circuit
Room temperature sensor,
system circuit A1

Open circuit
Room temperature sensor,
mixing valve circuit M2

Open circuit
Room temperature sensor,
mixing valve circuit M3

LON communication module

Check room temperature sensor
(see page 112)

Check room temperature sensor
(see page 112)

Check room temperature sensor
(see page 112)

Check room temperature sensor
(see page 112)

Check connection
(see page 96)

Retrieving fault codes from the fault memory (fault history)

All faults which have occurred are stored and can be retrieved by scanning.
The scanning sequence starts with the most recently stored fault code.

1 23 4 5 67

1. Press and simultaneously for
approx. 2 seconds.

2. Access the individual fault codes by
pressing the or button.

Sequence of
stored fault
codes

1

.
.
.

10

Fault code

Last (most recent)
fault code

.
.
.

Last fault code but
nine

Scanning of fault history is
activated.

All stored fault codes can be
deleted by pressing .

5285 941 v.1.6

3. Press .

Scanning of fault history is
terminated.

85

Functional description

Boiler temperature control

Brief description

The boiler water temperature is
controlled by switching the burner
stages or modulation on and off.
The desired boiler water temperature
value is determined by the set-point
supply temperature value of the boiler
circuit (A1), the mixing valve circuits
or the heating circuits connected via
the LON BUS, through the external
request facility and the desired
domestic hot water temperature, and
is dependent on the boiler and the
heating and control facilities installed.
In conjunction with Therm-Control:
The desired boiler water temperature
is increased when the temperature
falls below the set-point value on
the sensor of the Therm-Control.

Functions

The boiler water temperature is
measured via a multiple sensor well by
three sensors separately:
Fixed high limit FHL (liquid

expansion)

Adjustable high limit AHL (liquid

expansion)

Boiler temperature sensor BTS

(change in resistance PT 500)

When the domestic hot water tank
is heated up, a desired boiler water
temperature is selected which is
20°C / 36°F higher than the desired
DHW tank water temperature (this
value can be changed via coding
address ”60”).

Upper limits of control range

Fixed high limit FHL 110°C / 230°F,

can be adjusted to 99°C / 210°F

Adjustable high limit AHL 95°C, can

be adjusted to 100°C / 212°F

Electronic maximum limit

Setting range: 20 to 127°C / 68 to
261°F
The maximum limit for the boiler
water temperature is defined in
coding address ”06”.

Coding addresses which influence
the boiler temperature control

02 to 06, 08 to 0b, 13 to 1C
See page 114 onwards for
description.

Lower limit of control range

The control unit regulates the

boiler water temperature in
normal operation and in the
frost protection mode according
to the boiler concerned (boiler
coding card).

Control sequence

Boiler temperature falls

The burner switch-on signal is set for
a boiler water temperature set-point
value of –2°C / -4°F, and the burner
starts its own monitoring program.
Depending on the range of additional
control facilities and the method of
firing, burner override can be delayed
by a few minutes.

86

Boiler temperature rises

The switch-off point of the burner is
defined by the switch-off differential
(coding address ”13”).

5285 941 v.1.6

Heating circuit control

Brief description

Functional description

The control unit has control loops for a
system circuit and two mixing valve
circuits.

The supply temperature set-point value
is determined by the outdoor
temperature, the desired room
temperature, the operating mode and
the heating curve.

Functions

The heating circuit is dependent on the
boiler water temperature and its control
range limits.
The only control element is the heating
circuit pump.
The supply temperature of the mixing
valve circuits is measured by the
supply temperature sensor (contact
sensor).

Time program

The timer of the control unit changes
the operating mode at the programmed
times in the ”Central heating and
DHW” heating program, switching
between ”Central heating with normal
room temperature” and ”Central
heating with reduced room
temperature”.
Each operating mode has its own
set-point value.

Outdoor temperature

A heating curve must be adjusted to
match the control unit to the building
and the heating system.
The heating curve determines the
set-point boiler water temperature
value as a function of the outdoor
temperature. Control takes place on
the basis of the mean outdoor
temperature. This is derived from the
actual and the damped outdoor
temperature.
The heating curve can be changed via
the set-point or operating mode
selector switches.

The supply temperature of the mixing
valve circuits is controlled by opening
and closing the mixing valves in steps.
The mixing valve motor control varies
the actuation and interval times as a
function of the control difference
(control deviation).

Domestic hot water temperature

With priority control:

While the DHW tank is being heated,
the set-point supply temperature
value is set to 0°C / 32°F .
The heating circuit pump is
switched off.

Without priority control:

The heating circuit control continues
to operate as normal with the
set-point value unchanged.

With modulating priority control

(only in conjunction with mixing
valve circuit):
The heating circuit pump remains
switched on. The set-point supply
temperature of the heating circuit
is lowered as long as the set-point
boiler water temperature is not
reached while the DHW tank is
being heated. The set-point supply
temperature is dependent on the
difference between the set-point and
the current boiler water temperature,
the outdoor temperature, the heating
curve slope and the setting of the
coding address ”A2”.

The supply temperature of the system
circuit corresponds to the boiler water
temperature.

Coding addresses which influence the
heating circuit control

9F
A2 to A7, A9,
C4 to C7, C8
F1, F2.
See page 114 onwards for description.

Room temperature

In conjunction with room
temperature dependent control:

Compared with the outdoor
temperature, the room temperature
has a greater influence on the
set-point boiler water temperature.
The magnitude of this influence can
be changed via coding address ”b2”.
In conjunction with mixing valve
circuit:
With control differences
(i.e. deviations from the current
value) of over 2°C / 4°F room
temperature, this influence can be
intensified (via coding address ”b6”,
rapid heating/setback).

5285 941 v.1.6

87

Functional description

Heating circuit control

Functions (continued)

Summer energy saving function
(heating circuit pump logic)

If the outdoor temperature is higher
than the preset room temperature
set-point value, the heating circuit
pump is switched off and the set-point
supply temperature value is set to
0°C / 32°F.
The switching threshold can be
individually selected via coding address
”A5”.

Extended summer energy saving
function

The heating circuit pump can be
switched off
If the outdoor temperature exceeds a

value preselected via coding address
”A6”

If the set-point room temperature is

reduced via coding address ”A9”

In conjunction with mixing valve

circuit:
If the mixing valve has been closed
for longer than 12 minutes (mixing
valve energy saving function, coding
address ”A7”)

Slab curing function

(only in conjunction with mixing valve
circuit)

(continued)

System dynamics – mixing valve
circuit (only in conjunction with

mixing valve circuit)

The control behaviour of the mixing
valve can be influenced via coding
address ”C4”.

Frost protection

A supply temperature of 15 to 22°C /
59 to 72°F is assured for outdoor
temperatures below +1°C / 34°F
(two-point control).
For possible changes, see coding
address ”A3” (variable frost threshold).

Therm-Control

Heating circuit output reduction takes
place if the boiler return temperature
falls below the setpoint value (value
read on the therm-control sensor).
Heating circuit mixing valves modulate
closed until the Therm-control sensor
is satified.

Supply temperature control

Differential temperature:
The differential temperature can be
selected via coding address ”9F”,
factory setting: 8°C / 14°F.

The differential temperature is the
minimum difference by which the
boiler water temperature should
exceed the highest currently required
supply temperature of the mixing
valve circuit.

System with only one mixing

valve circuit:
The desired boiler water
temperature is automatically
controlled at 8°C / 14°F above
the desired supply temperature
value.

System with heating circuit and

mixing valve circuit:
The desired boiler water
temperature is controlled according
to its own heating curve. The
temperature difference of
8°C / 14°F.
from the desired supply
temperature is preset in the
factory.

Please note:

The slab curing function is selectable
on the basis of four different
temperature curves. The curves are
activated via coding address ”F1”
(see page 134).

When the slab curing function is
activated, the heating circuit pump of
the mixing valve circuit is switched on
and the supply temperature is
controlled according to the selected
curve. When the slab curing time (30
days) has expired, the mixing valve
circuit is automatically controlled on
the basis of the preset parameters.

88

Boiler water temperature/

supply temperature in °C

Outdoor temperature in °C

A Max. boiler water temperature
B Slope = 1.8 Heating circuit
C Slope = 1.2 Mixing valve circuit

D Boiler water temperature

(with differential temperature =
8°C / 14°F.)

E Minimum boiler water

temperature

5285 941 v.1.6

Functional description

Heating circuit control

Functions (continued)

Upper limit of control range

Electronic maximum limit
Setting range:
1 to 127°C / 34 to 260°F.
Change via coding address ”C6”.

Please note:

The maximum limit does not replace
the limit thermostat required for
underfloor heating systems.

Limit thermostat for underfloor heating
systems:
The limit thermostat switches the
heating circuit pump off when the
supply temperature rises above the
preset value. In this situation, the
supply temperature cools down only
slowly, i.e. automatic re-starting can
take several hours.

(continued)

Lower limit of control range

Electronic minimum limit
Setting range:
1 to 127°C / 34 to 261°F.
Change via coding address ”C5”.

Control sequence

Mixing valve circuit

The mixing valve motor is not activated
within the ”neutral zone”
(±1°C / 2°F).

Supply temperature falls

(Set-point value –1°C / -2°F)
The mixing valve motor receives the
signal ”Open mixing valve”.
The greater the control difference, the
longer the duration of the signal and
the shorter the duration of the
intervals.

Supply temperature rises

(Set-point value +1°C / +2°F):
The mixing valve motor receives the
signal ”Close mixing valve”.
The greater the control difference, the
longer the duration of the signal and
the shorter the duration of the
intervals.

5285 941 v.1.6

89

Functional description

DHW tank temperature control

Brief description

The DHW tank temperature control is a
constant value control. It operates on
the basis of switching the circulation
pump for heating the DHW tank on and
off.
The switching differential is ±2.5°C /

4.5°F.

Functions

Time program

An automatic or an individual time
program can be selected for domestic
hot water heating and the DHW
circulation pump.
In the automatic program, domestic
hot water heating precedes the heat-up
phase of the heating circuit by 30
minutes. On systems with several
heating circuits, the time program is
based on the switching times of the
first heating circuit to be heated.
In the individual time program, up to
four switching times per day can be
set on the timer for domestic hot water
heating and the DHW circulation pump.
Once started, heating of the DHW tank
is always completed regardless of the
time program.
The switching times for domestic hot
water heating and the DHW circulation
pump are effective for all heating
circuits. Individual switching times can
be assigned to each heating circuit via
the coding address ”7F”.

During DHW tank heating, a constant
maximum boiler water temperature is
set and space heating is switched off
(DHW tank priority control optional).

Frost protection function

If the domestic hot water temperature
falls below 10°C / 50°F, the
domestic hot water DHW tank is
heated to 20°C / 68°F.

Additional function for domestic hot
water heating

This function is activated when a
second DHW setpoint value is selected
via coding address ”58” and the 4th
activation period for domestic hot
water heating is activated.

Desired domestic hot water
temperature

The desired domestic hot water
temperature can be set in the range
of 10 to 60°C / 50 to 140°F. The
set-point range can be extended to
95°C / 203°F via coding address
”56”.
The desired domestic hot water
temperature can be set on the
programming unit of the control unit
and on the Vitotrol 300 remote control
(if installed).
The set-point value can be assigned via
coding address ”66”.

Coding addresses which influence
the DHW tank temperature control

55, 56, 58 to 62, 64, 66, 70 to 75,
7F, A2.
See page 114 onwards for description.

DHW circulation pump

The DHW circulation pump supplies
hot water to the take-off points at
selectable times. Up to four
switching times can be set on the
timer.

Additional control facilities

The domestic hot water supply can
be blocked and released via
changeover of the heating program.

System with DHW tank loading system

The functions described above also
apply in conjunction with DHW tank
loading systems.

Set the following codings:
”4C: 1”, ”4E: 1”, ”55: 3”.

90

5285 941 v.1.6

Functional description

DHW tank temperature control

Control sequence

DHW tank temperature falls

(Set-point value –2.5 °C / 4.5 °F,

selectable via coding address ”59”)
The desired boiler water temperature
is set 20 K higher than the DHW
temperature set-point value (selectable
via coding address ”60”).

The circulation pump for heating the
DHW tank is switched on immediately
(Coding ”61: 01”).

Boiler temperature-dependent switching
of the circulation pump for heating the
DHW tank (Coding ”61: 00”):
The circulation pump is switched on
when the boiler water temperature is
7°C / 13°F higher than the domestic
hot water temperature.

With priority control:

(Coding ”A2: 2”)
The supply temperature set-point
value is set to 0 °C / 32°F when the
DHW tank is being heated. The
mixing valve is closed and the
heating circuit pump is switched off.

Without priority control:

The heating circuit control continues
to operate as normal with the
setpoint value unchanged.

With modulating priority control (only

in conjunction with mixing valve
circuit):
The heating circuit pump remains
switched on. The desired supply
temperature is lowered as long as the
desired boiler water temperature is
not reached while the DHW tank is
being heated. The desired supply
temperature is dependent on the
difference between the desired and
the current boiler water temperature,
the outdoor temperature, the heating
curve slope and the setting of the
coding address ”A2”.

5285 941 v.1.6

DHW tank temperature rises

(Set-point value +2.5 / 4.5°F)
The boiler water temperature set-point
value is reset to the weather­compensated value.

When the DHW tank has been

Circulation pump for heating the

With priority control

With optimized DHW tank heating

(continued)

heated up, the circulation pump for
heating the DHW tank continues to
run until:
the temperature difference between

the boiler water and domestic hot
water is less than 7°C / 13°F, or

the desired, weather-compensated

boiler water temperature is
reached, or

the desired domestic hot water

temperature is exceeded by

5°C / 9 °F.
The max. run-on time is 15 minutes
(selectable via coding address ”62”).

DHW tank without run-on time
(Coding ”62: 00”):
The circulation pump is switched off
immediately.

(Coding ”A2: 2”):
The supply temperature set-point
value is reset to the weather­compensated value.
The heating circuit pump is
switched on.

(Coding ”55: 1”):
Optimized DHW tank heating takes
into account the rate at which the
temperature increases during
domestic hot water heating.
It also takes into account whether
the boiler must supply heat for space
heating purposes after heating up the
DHW tank or whether the residual
heat of the boiler should be
transferred to the domestic hot
water DHW tank.
The control unit determines the
switch-off time of the burner and the
circulation pump accordingly so that
the desired domestic hot water
temperature is not substantially
exceeded after DHW tank heating is
completed.

91

Additional information

Overview

Page

Technical data 93

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System components

Line-voltage motherboard 94
Low-voltage motherboard 94
Power supply unit board 94
Electronics board 94

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Mixing valve extension circuit board 95
Electronics board for mixing valve extension 95
Optolink/emissions test switch board 95
Programming unit 95

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Front panel with heating circuit selector buttons 96
Fuse box 96

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LON communication module 96
Boiler coding card 97
Fuses 97

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TEST button 97
Fixed high limit 98

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Adjustable high limit 98
Outdoor temperature sensor 99
Boiler temperature sensor and DHW tank temperature sensor 101
Strap-on temperature sensor/immersion temperature sensor 102
Flue gas temperature sensor 104
Installation examples 105
Vitotrol 200 106
Vitotrol 300 108

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Connection of two or more remote controls 110
Room temperature sensor 112
Input Module 0 to 10V 113

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

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Coding 1

Call up coding level 1 114
Codings 114

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Coding 2

Call up coding level 2 116
Reset codings to factory settings 116
Overview of all codings 116

Wiring diagram 135

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92

5285 941 v.1.6

Technical data

Additional information

Rated voltage: 120V
Rated frequency: 60 Hz
Rated current: 2 x 6A
Power
consumption: 10W
Protection class: I
Degree of IP 20 D to
protection: EN 60 529, to be

guaranteed by

mounting/integration
Method of Type 1B to
operation: EN 60 730-1

Ambient temperature

During

operation: 0 to 40°C /

32 to 104°F
For use in boiler rooms
(normal ambient conditions)

During storage and

transport: –20 to 65˚C /

-4 to 149°F

Relay outputs at 120V for
Heating circuit

pumps or control
output sÖ: 2 FLA, 120 VAC

Circulation

pump for heat­ing the DHW tank
sA: 2 FLA, 120 VAC

DHW circulation

pump sK: 2 FLA, 120 VAC

Shunt

pump sL: 2 FLA, 120 VAC

Central fault

indicator gÖ: 2 FLA, 120 VAC

Mixing valve

motor return
temperature
raising
or
3-way valve
DHW tank heating system
or
mixing valve
motor gS: 0.1 FLA,

120 VAC

*1

Burner

plug fA: 4 FLA, 120 VAC
plug lÖ:
– 2-stage 0.5 FLA 120 V~
– modulating 0.1 FLA 120 V~

*1

*1

*1

*1

*1

1

*

Total max. 6 A 120V

5285 941 v.1.6

93

Additional information

System components

Line voltage motherboard, Part No. 7165 782

Low-voltage motherboard, Part No. 7820 290

The motherboard contains:
Relays and outputs for activating

the pumps, the control elements
and the burner

Plug-in location for power supply

unit board and boiler control
section

The motherboard contains:
Plugs for sensors, communication

connections and external
equipment

Plug-in locations for electronics

board, LON communication module,
programming unit, boiler coding
card and Optolink board

Power supply unit board, Part No. 7823 991

Electronics board, Part No. 7828 193

The power supply unit board
contains the low-voltage supply
for the entire electronics.

The board contains the
microprocessor with the software

When replacing the board:

1. Make a note of codings and
settings on the control unit.

2. Replace the board.

3. Set coding ”8A: 176” and set

coding address ”92” (not listed
in the overview) to ”92: 165”.

94

5285 941 v.1.6

Additional information

System components

Mixing valve extension board, Part No. 7820 193

Electronics board, Part No. 7829 790

(continued)

The board contains the relays for
activating the mixing valve motor
and the heating circuit pump of the
mixing valve circuits M2 and M3.

This is connected to the mixing
valve extension board.

All data are processed and the
outputs (relays) activated.

Optolink/emissions test switch board, Part No. 7820 165

The circuit board contains:

Operating status indicator
Fault indicator
Optolink laptop interface
Emissions test switch

Programming unit, Part No. 7823 986

Emissions test switch for flue gas
measurements with the boiler
operated with constant boiler water
temperature for a short time.
The burner is switched on

(this can be delayed if the system
incorporates a fuel preheater)

all pumps are switched on
the mixing valve remains in its

control mode

the boiler water temperature is

controlled by the adjustable high
limit ”R”.

The programming unit is inserted in
the control unit.

For setting:

Heating program
Set-point values
Switching times
Heating curve (shift and slope)
Date
Time
Energy saving and party mode

5285 941 v.1.6

For displaying:

Temperatures
Operating status information
Faults

95

Additional information

System components

Front panel with heating circuit selector buttons, Part No. 7818 623

Fuse box, Part No. 7820 172

(continued)

For displaying and selecting the
heating circuit.

The fuse box contains:

Fixed high limit
Adjustable high limit
Fuses
Heating system switch
TEST button

LON communication module, Part No. 7172 173 Accessory

A

LON

LON

C

A Control unit or Vitocom 300
B Connecting cable for data transfer

between the control units
(accessory)

C Terminal resistor,

Part No. 7143 497

A A

LON

B

LON

B

LON

C

The communication module is
inserted in the control unit.
Interruption of communication is
indicated.

LON

1 terminal resistor is inserted on
each of the first and last control
units.

96

5285 941 v.1.6

Additional information

System components

Boiler coding card

Fuses

F1

(continued)

Vitotronic 300
in conjunction with

Vitorond 200 1020 7820 142
Vitocrossal 300, Type CT3 1040 7820 144
Vitocrossal 200, Type CM2 1041 7820 145

Boiler coding card Part No.

F1: 6.3 A, 250 V for protecting
the control elements, pumps and
electronics
Mounting location: see drawing
Part No. 7404 365

F2: 6.3 A, 250 V for protecting
the burner
Mounting location: see drawing
Part No. 7404 365

F2

TEST button, Part No. 7819 314

For checking the fixed high limit.
See description on page 65.

5285 941 v.1.6

97

Additional information

System components

Fixed high limit, Part No. 7820 036

Adjustable high limit, Part No. 7817 531

(continued)

The fixed high limit has a factory setting of 110°C/ 230°F.
Electromechanical temperature switch based on the liquid expansion principle

with interlock

Intrinsically safe; interlocking also takes place if the capillary tube is leaking or

if ambient temperatures are below –10°C / 14°F

Limits the boiler water temperature to the maximum permissible value by

cutting out and interlocking

Can be adjusted with the slotted screw A at the rear of the unit to 99°C /

210°F (cannot be reset to 110°C / 230°F once adjusted)

Reset unit by pressing the reset button ”E” on the front of the programming

unit if the temperature has fallen approx. 15 K below the shut down temperature

Central fastening M 10, capillary 3600 mm long
Tests:

Functional check via TÜV TEST button

The adjustable high limit has a factory setting of 95°C / 203°F
Electromechanical temperature switch based on the liquid expansion principle
Controls the maximum boiler water temperature (e.g. in emissions test mode)
Can be adjusted to 100°C / 212°F by altering the setting

of the stop dial or by removing the cams

IMPORTANT

Set the lower limit at least 20°C / 36°F
higher than the domestic hot water
temperature, the upper limit at least
15°C / 27°F lower than the fixed
high limit.

Adjusting shaft 6 mm / 0.27 inches,

flat topped
Adjusting knob pushed onto shaft
from front

Capillary 3600 mm / 141.7 inches long

Sensor 3 mm / 0.1inches thick,
180 mm / 7.1inches long

Tests:

Functional check via emissions test mode

98

5285 941 v.1.6

Additional information

System components

(continued)

Outdoor temperature sensor, Part No. 7820 148

Outdoor temperature sensor

600

580

560

540

520

500

480

Resistance in

460

Connection

Check sensor

1. Remove plug !.

2. Check the sensor resistance at

terminals 1 and 2 of the plug.

Outdoor
temperature in

Resistance
in ΩΩΩΩ

ºC / ºF

–10 / 14

0 / 32

20 / 68

480
500
546

3. Disconnect cores from the sensor,
if actual values deviate severely from
the curve, repeat the sensor
measurement and compare with
the actual temperature.

440

420

400

-40 -30 -20 -10 0 10 20 30

-40 -22 -4 14 32 50 68 86

Outdoor temperature in ºC / ºF

4. Depending on the result, replace
cable or outdoor temperature
sensor.

5. Scan actual temperature.

Specification

Protection: IP 43
Permissible ambient temperature
during operation, storage and
transport:

–40 to +70ºC
–40 to 158ºF

5285 941 v.1.6

99

Additional information

System components

Outdoor temperature sensor

1.

4.

(continued)

The outdoor temperature sensor should be mounted 2 to 2.5 metres / 6.5 to 8 ft
above ground level on the north or north-west facing wall of the building. In the
case of multi-storey buildings, it should be mounted in the upper half of the
second storey.
Make sure that the sensor is not located over windows, doors and air vents,
nor immediately beneath a balcony or guttering.
Do not paint over the outdoor temperature sensor housing.

5.

3.

1. Remove the cap.

2. Mount the bottom part of the

sensor housing.

3. Pull the sensor wire through the
opening in the terminal
compartment and through the
strain relief provided.

4. Connect the wires to the
terminals.

5. Place the cap over the outdoor
temperature sensor.

A

2.

WARNING

When extending wire, there is the
possibility of exposure to electromagnetic
interference. Avoid running wires
beside or near high voltage 120/240
VAC conductors. If proximity to high
voltage conductors cannot be avoided,
use stranded, twisted pair or shield
design wire. Ensure that only one end
of the shielding is grounded.

A Outdoor temperature sensor

1

100

5285 941 v.1.6