Ariston 47-116-17 User Manual

Installation
Instructions
Type C Boilers

G.C.N: 41-116-03

47-116-17

LEAVE THESE INSTRUCTIONS
WITH THE END-USER

Condensing

Country of destination: GB

2752275

This manual is an integral and essential part of the product. It should
be kept with the appliance so that it can be consulted by the user and
our authorised personnel.

Please carefully read the instructions and notices about the unit
contained in this manual, as they provide important information
regarding the safe installation, use and maintenance of the product.

For operating instructions please consult the separate User’s Manual.

1. GENERAL INFORMATIONTABLE OF CONTENTS

1. GENERAL INFORMATION

1.1. GENERAL INFORMATION

1.3. OVERALL V

IEW

2. INSTALLATION

2.1. REFERENCE S

TANDARDS

2.2. SITING THE APPLIANCE

2.3. OVERALL DIMENSIONS

2.4. MINIMUM CLEARANCES

2.5. MOUNTING THE APPLIANCE

2.6. E

LECTRICAL CONNECTION

2.7. G

AS CONNECTION

2.8. W

ATER CONNECTIONS

2.9. FLUE CONNECTIONS

2.10. A

CCESSORY CONNECTION

2.10.1. R

OOM THERMOSTAT CONNECTION

2.10.2. REMOTE CONTROL CONNECTION

2.10.3. ACCESSORY CONNECTION TERMINAL BLOCK

2.10.4. CYLINDER TEMPERATURE PROBE CONNECTION

2.10.5. REMOTE CONTROL TERMINAL BLOCK AND
CYLINDER PROBE

2.11. E

LECTRICAL DIAGRAM

2.12. WATER CIRCUIT DIAGRAMS

3. COMMISSIONING

3.1. INITIAL PROCEDURES

3.2. REMOVING THE CASING

3.3. C

ONTROL PANEL

3.4. INITIAL START-UP

3.5. DISPLAY:MESSAGES SHOWN DURING
N

ORMAL OPERATION

3.6. OPERATING PARAMETERS

3.6.1. CONTROL MODES

3.6.2. O

UTDOOR SENSOR

3.6.3. S

ETTINGS D

ISPLAY

3.7. REGULATIONS

3.7.1. POTENTIOMETER

3.7.2. SETTING THE TEMPERATURE FIELD

3.7.3. COMFORT KEY/HEATING ONLY

3.7.4. POST-CIRCULATION OF THE PUMP

3.7.5. TEST MODE

3.7.6. R

EGULATION MENU TABLE

3.8. BOILER SAFETY SYSTEMS

3.9. COMBUSTION ANALYSIS

3.10. D

RAINING

4. GAS ADJUSTMENTS

4.1. O

VERALL VIEW

4.2. PRELIMINARIES

4.3. GAS REGULATION

4.3.1. T

EST OF THE CONNECTION PRESSURE

4.3.2. REGULATION OF THE THERMAL POWER

4.4. CHANGING THE TYPE OF GAS

4.5. O

PERATING TESTS

5. ZONE V ALVES

6. MAINTENANCE

6.1. GENERAL REMARKS

6.2. C

LEANING THE PRIMARY EXCHANGER

6.3. CLEANING THE CONDENSATE TRAP

6.4. OPERATIONAL TEST

7. TECHNICAL INFORMATION

1.1. G

ENERAL I

NFORMATION

Read the instructions and recommendations in these Installation
Instructions carefully to ensure proper installation, use and
maintenance of the appliance.

Keep this manual in a safe place. You may need it for your own
reference while our Servicing Centre technicians or your installer
may need to consult it in the future.

This is a combined appliance for the production of central heating
(C.H.) and domestic hot water (D.H.W.).

This appliance must be used only for the purpose for which it is
designed.
The manufacturer declines all liability for damage caused by
improper or negligent use.

No asbestos or other hazardous materials have been used in the
fabrication of this product.

Before connecting the appliance, check that the information shown
on the data plate and the table on pages 4-5 comply with the electric,
water and gas mains of the property. You will find the data plate on
the reverse of the control panel.
The gas with which this appliance operates is also shown on the
label at the bottom of the boiler.

Do not install this appliance in a damp environment or close to
equipment which spray water or other liquids.

Do not place objects on the appliance.
Do not allow children or inexperienced persons to use the appliance

without supervision.
If you smell gas in the room, do not turn on light switches, use the

telephone or any other object which might cause sparks.
Open doors and windows immediately to ventilate the room.
Shut the gas mains tap (on the gas meter) or the valve of the gas
cylinder and call your Gas Supplier immediately.
If you are going away for a long period of time, remember to shut the
mains gas tap or the gas cylinder valve.

Always disconnect the appliance either by unplugging it from the
mains or turning off the mains switch before cleaning the appliance
or carrying out maintenance.

In the case of faults or failure, switch off the appliance and turn off
the gas tap.Do not tamper with the appliance.
For repairs, call your local Authorised Servicing Centre and request
the use of original spare parts. For in-guarantee repairs contact MTS
(GB) Limited

The technical information and instructions provided herein below are
intended for the installer so that the unit may be installed correctly
and safely.

The installation and initial start-up of the boiler must be by a CORGI
Approved Installer in compliance with the installation standards
currently in effect, as well as with any and all local health and safety
standards i.e.CORGI.

This appliance must be installed by a competent installer in
accordance with the current Gas Safety (installation & use)
Regulations.

The installation of this appliance must be in accordance with the
relevant requirements of the current Gas Safety (installation & use)
Regulations, the Local Building Regulations, the current I.E.E.Wiring
Regulations, the byelaws of the local water authority, and in Scotland,
in accordance with the Building Standards (Scotland) Regulation and
Health and Safety document No.635 “Electricity at work regs. 1989”.
Installation should also comply with the following British Standard
Codes of Practice:

2. INSTALLATION

2.1. R

EFERENCE STANDARDS

Low pressure
pipes BS 6891 1988

Boilers of rated input
not exceeding 60 kW BS 6798 1987

Forced circulation hot
water system BS 5449 1990

Installation of gas hot water
supplies for domestic purposes
( 2

nd

family gases) BS 5546 1990

Flues BS 5440-1 1990
Air supply BS 5440-2 1989

3

275

24 MFFI

LEGEND:

1. Flue connector

2. Heating flow temperature probe

3. Mixer

4. Condensate collector

5. Expansion vessel

6. Condensate trap (tube)

7. Condensate trap

8. Diverter valve

9. Main circuit flow switch

10. Domestic hot water temperature probe

11. Control panel

12. Gas valve

13. Domestic hot water flow switch

14. Drain valve

15. Safety valve (3 bar)

16. Secondary heat exchanger

17. Circulation pump with automatic air release valve

18. Heating return temperature probe

19. Sealed combustion chamber

20. Combustion chamber inspection hatch

21. Fan

22. Ignition and detection electrode

23. Main heat exchanger (aluminium)

24. Automatic by-pass

25. Silencer

F

IG. 1.1

1.3. OVERALL VIEW

24 RFFI SYSTEM

2.3. OVERALL DIMENSIONS

FIG. 2.1

24 MFFI

24 RFFI SYSTEM

4

275

The appliance may be installed in any room or indoor area, although
particular attention is drawn to the requirements of the current I.E.E.
Wiring Regulations, and in Scotland, the electrical provisions of the
Building Regulations applicable in Scotland, with respect to the
installation of the combined appliance in a room containing a bath or
shower.

Where a room-sealed appliance is installed in a room containing
a bath or shower the boiler and any electrical switch or
appliance control, utilising mains electricity should be situated
so that it cannot be touched by a person using the bath or
shower.

The location must permit adequate space for servicing and air
circulation around the appliance as indicated in paragraph 2.4.
The location must permit the provision of an adequate flue and
termination.
For unusual locations special procedures may be necessary.
BS 6798-1987 gives detailed guidance on this aspect.
A compartment used to enclose the appliance must be designed
specifically for this purpose. No specific ventilation requirements are
needed for an installation within a cupboard.
This appliance is not suitable for outdoor installation.

The type C appliances (in which the combustion circuit, air vent
intake and combustion chamber are air-tight with respect to the
room in which the appliance is installed) can be installed in any
type of room.

There are no limitations with respect to ventilation and the volume of
the room itself. The boiler must be installed on a solid, permanent
wall to prevent access to the electrical parts (when live) through the
aperture on the back frame.

2.2. SITING THE APPLIANCE

L

EGEND:

A = Central Heating Flow (3/4”)
B = Domestic Hot Water Outlet (1/2”)
C = Gas Inlet (3/4”)
D = Domestic Cold Water Inlet (1/2”)
E = Central Heating Return (3/4”)
F = Cylinder Flow (3/4”)
G = Cylinder Return (3/4”)
H = Condensate discharge

20

=

67 67

65 65

155

181

100

(A-B-D-E)

208 (C)

=

Fasten the boiler in place using the template and anchors supplied
with the unit. It is highly recommended that a spirit level be used to
position the boiler so that it is perfectly level.
For additional information, please consult the instructions contained
in the connection kit and the flue kit.

2.5. MOUNTING THE APPLIANCE

2.6. ELECTRICAL CONNECTION

For safety purposes, have a competent person carefully check the
electrical system in the property, as the manufacturer will not be held
liable for damage caused by the failure to earth the appliance
properly or by anomalies in the supply of power. Make sure that the
residential electrical system is adequate for the maximum power
absorbed by the unit, which is indicated on the rating plate. In
addition, check that the section of cabling is appropriate for the
power absorbed by the boiler.

The boiler operates with alternating current, as indicated in the
technical data table (1.2), where the maximum absorbed power is
also indicated. Make sure that the connections for the neutral and live
wires correspond to the indications in the diagram. The appliance
electrical connections are situated on the reverse of the control panel
(see the servicing manual for further information)

FIG. 2.3

2.7. GAS CONNECTION

The local gas region contractor connects the gas meter to the
service pipe.
If the gas supply for the boiler serves other appliances ensure that an
adequate supply is available both to the boiler and the other
appliances when they are in use at the same time.
Pipe work must be of an adequate size. Pipes of a smaller size than
the boiler inlet connection should not be used.

5

275

In order to allow for access to the interior of the boiler for
maintenance purposes, the boiler must be installed in compliance
with the clearance requirements indicated in the diagram below.

2.4. MINIMUM CLEARANCES

FIG. 2.2

24 MFFI

24 MFFI SYSTEM

IMPORTANT!

In the event that the power supply cable must be changed, replace it
with one with the same specifications. Make the connections to the
terminal board located within the control panel, as follows:

- The yellow-green wire should be connected to the terminal marked
with the earth symbol; make sure to re-use the ferrule mounted on
the other supply cord;

- The blue wire should be connected to the terminal marked “N”;

- The brown wire should be connected to the terminal marked “L”.
Note: The diagrams for the electrical system are indicated in section

2.11.

Warning,this appliance must be earthed.

External wiring to the appliance must be carried out by a qualified
technician and be in accordance with the current I.E.E. Regulations
and applicable local regulations. The Genus range of boilers are

supplied for connection to a 230 V~ 50 Hz supply.

The supply must be fused at 3 A.

The method of connection to the electricity supply must facilitate
complete electrical isolation of the appliance, by the use of a fused
double pole isolator having a contact separation of at least 3 mm in
all poles or alternatively, by means of a 3 A fused three pin plug and
unswitched shuttered socket outlet both complying with BS 1363.
The point of connection to the Electricity supply must be readily
accessible and adjacent to the appliance unless the appliance is
installed in a bathroom when this must be sited outside the
bathroom.

6

275

2.8. WATER CONNECTIONS

L

EGEND:

A = Central Heating Flow
B = Domestic Hot Water Outlet
C = Gas Inlet
D = Domestic Cold Water Inlet)
E = Central Heating Return
F = Cylinder Flow
G = Cylinder Return
H = Condensate discharge
I = Safety valve discharge

C

ENTRAL HEATING

Detailed recommendations are given in BS 6798:1987 and BS 5449­1:1990, the following notes are given for general guidance.

P

IPE WORK:

Copper tubing to BS EN 1057:1996 is recommended for water
pipes. Jointing should be either with capillar y soldered or
compression fittings.
Where possible pipes should have a gradient to ensure air is
carried naturally to air release points and water flows naturally to
drain taps.
The appliance has a built-in automatic air release valve, however
it should be ensured as far as possible that the appliance heat
exchanger is not a natural collecting point for air.
Except where providing useful heat, pipes should be insulated to
prevent heat loss and avoid freezing.
Particular attention should be paid to pipes passing through
ventilated spaces in roofs and under floors.

B

Y-PASS:

The appliance includes an automatic by-pass valve, which
protects the main heat exchanger in case of reduced or
interrupted water circulation through the heating system, due to
the closing of thermostatic valves or cock-type valves within the
system.

A

C

B

D E

I

A

C

G

D E

I

F

VIEW OF THE BOILER CONNECTIONS

FIG. 2.4

24 MFFI

24 MFFI SYSTEM

H

H

SYSTEM DESIGN:

This boiler is suitable only for sealed systems.

DRAIN COCKS:

These must be located in accessible positions to permit the
draining of the whole system. The taps must be at least 15mm
nominal size and manufactured in accordance with BS
2870:1980.

S

AFETY VALVE DISCHARGE:

The discharge should terminate facing downwards on the exterior
of the building in a position where discharging (possibly boiling
water & steam) will not create danger or nuisance, but in an easily
visible position, and not cause damage to electrical components
and wiring.
The discharge must not be over an entrance or a window or any
other type of public access.

C

ONDENSATE DISCHARGE:

The condensate discharge hose from the boiler must be inserted
by at least 50 mm into a suitable acid resistant pipe - e.g. plastic
waste or overflow pipe. The condensate discharge pipe must have
a continuous fall and preferably be installed and terminated within
the building to prevent freezing.
The discharge pipe must be terminated in a suitable position:

i) Connecting in to an internal soil stack (at least 450 mm above

the invert of the stack).A trap giving a water seal of at least 75
mm must be incorporated into the pipe run , there also must
be an air break upstream of the trap.

ii) Connecting into the waste system of the building such as a

washing machine or sink.The connection must be upstream of
the washing machine/sink (If the connection is down stream of
the waste trap then an additional trap giving a minimum water
seal of 75 mm and an air break must be incorporated in the
pipe run, as above.

iii) Terminating into a gully, below the grid level but above the

water level.

iv) Into a soakway.

N

OTE: If any condensate pipe work is to be installed externally,

then it should be kept to a minimum and be insulated with a
waterproof insulation and have a continuous fall.

A

IR RELEASE POINTS:

These must be fitted at all high points where air naturally collects
and must be sited to facilitate complete filling of the system.
The appliance has an integral sealed expansion vessel to
accommodate the increase of water value when the system is
heated.
It can accept up to 7 l (1.5 gal) of expansion water. If the heating
circuit has an unusually high water content, calculate the total

FIG. 2.5

Fitting the connection kit to
the ecoGENUS 24 RFFI
SYSTEM only.

It will be noted that the kit has
two connections not required
for this boiler i.e. the domestic
cold inlet “D” and the domestic
hot water outlet “B” (see fig.

2.4).
Although the cold water main supply must be connected to the
isolation valve for the purpose of operating the filling-loop, the
isolation valve is NOT connected to the boiler and should be left
in the OFF position.
The D.H.W. outlet is capped-off on the boiler, therefore not
requiring the isolation valve to be used.
The ecoGENUS 24 RFFI SYSTEM has 2 x 3/4" B.S.P. male
threads for the cylinder flow and return. It is recommended that 2
x 22mm x 3/4" female iron fittings (not supplied) be used on these
connections (using P.T.F.E. tape), before the boiler is mounted on
the wall.

7

275

In F

IG. 2.11 below, several different types of flue systems are shown.

For additional information regarding the flue accessories, please
consult the Flue Pipe Accessories manual.

Coaxial

Systems

Twin Pipe

Systems

Exhaust Type

C

13

B

33

outlet of fumes in

chimney or exhaust flue

C13, C33, C

43

C

53,C83

B

23

Maximum Extension

Exhaust/Air

(m)

4

4

31 (S1=S2)

55 (S1+S2)

54 (S2)

Diameter

of Pipes

(mm)

Ø 60/100

Ø 60/100

Ø 80/80

Ø 80/80

Ø 80

TERMINAL POSITION mm

A - Directly below an open window or other opening 300
B - Below gutters, solid pipes or drain pipes 75
C - Below eaves 200
D - Below balconies or car-port roof 200
E - From vertical drain pipes and soil pipes 75
F - From internal or external corners 300
G - Above ground or below balcony level 300
H - From a surface facing a terminal 600

I - From a terminal facing a terminal 1200

J - From an opening in the car port

(e.g.door, window) into dwelling 1200
K - Vertically from a terminal in the same wall 1500
L - Horizontally from a terminal in the same wall 300

FIG. 2.6

2.9. FLUE CONNECTIONS

FLUE SYSTEM

The provision for satisfactory flue termination must be
made as described in BS 5440-1.
The appliance must be installed so that the flue terminal is
exposed to outdoor air .
The terminal must not discharge into another room or
space such as an outhouse or lean-to.
It is important that the position of the terminal allows a
free passage of air across it at all times.
The terminal should be located with due regard for the
damage or discolouration that might occur on buildings in
the vicinity.
In cold or humid weather water vapour may condense on
leaving the flue terminal.
The effect of such “steaming”must be considered.
If the terminal is less than 2 metres above a balcony,
above ground or above a flat roof to which people have
access, then a suitable terminal guard must be fitted.
When ordering a terminal guard, quote the appliance
model number.

A suitable terminal guard is available from:

TOWER FLUE COMPONENTS
Morley Road
Tonbridge
Kent TN9 1RA

R

ESIDUAL HEAD OF THE BOILER

expansion and add an additional sealed expansion vessel with
adequate capacity.

MAINS WATER FEED - CENTRAL HEATING:

There must be no direct connection to the mains water supply
even through a non-return valve, without the approval of the Local
Water Authority.

F

ILLING:

A temporary method for initially filling the system and replacing
lost water during servicing and initial filling (in accordance with
Water Supply Byelaw 14), is provided as an integral part of the
connection kit (see F

IG. 2.5). The flexible hose must be removed

once the system has been filled. The D.H.W. inlet valve on the
connection kit has two positions, one for winter and one for the
summer. This enables the flow-rate through the appliance to be
adjusted so that a sensible D.H.W. temperature may be achieved
throughout the year.

D

OMESTIC W

ATER

The domestic water must be in accordance with the relevant

recommendation of BS 5546:1990. Copper tubing to BS EN
1057:1996 is recommended for water carrying pipe work and
must be used for pipe work carrying drinking water.

The minimum acceptable spacing from the terminal to obstructions
and ventilation openings are specified in Fig.2.6

8

275

FIG

. 2.11

2.10. ACCESSORY CONNECTION

To carry out the connection for the roomstat or the outdoor sensor,
proceed as follows:

1. Unscrew the screws “A” and rotate the control panel forwards;

2. Insert the connection cable for the thermostat or the outdoor

sensor into the cable gland “B” and open the lid of the control
panel after having first unscrewed fastening screws “C”.

3. Insert the connecting cable into the cable clamp “D” shown in
the figure and fasten it.

4. Remove the grommet “E” shown in the figure, make a hole in it
and pass the connecting cable for the roomstat or the outdoor
sensor through it.

5a. In order to connect up the roomstat, remove the link that is

located in the “F” terminal (marked with the initials “TA”) and
connect the cables.

5b. To connect up the outdoor sensor, insert the cables into the “G”

clamp (marked with the initials “SE”).

6. Return the grommet “E” to its initial position, then close back
the lid and lastly return the control panel to its place.

7 If a remote time clock is to be fitted, disconnect the integral time

clock plug from the P.C.B.

8 Using a volt-free switching time clock, connect the switching

wires from the time clock following points 1-6 above.

9 If using a time clock and room thermostat, these must be

connected in series as per points 1-8 above.

Note: Only a two-wire type room thermostat can be used.

For details on fitting the D.H.W. probe (ecoGENUS 27
RFFI only), please consult the separate instruction
sheet supplied with the probe.
An anti-frost device is built-in to the appliance’s
electronic regulation system.

1

2.10.1. ROOM THERMOSTAT CONNECTION

2

3

4

B

D

A

C

E

F

G

E

9

275

Refer to the illustrations in section 2.10.1.

1. Unscrew the screws “A” and rotate the control panel forwards.

2. Insert the connecting cable of the under floor heating sensor into

the cable gland “B” and open the lid of the instrument panel
after having unscrewed the fastening screws “C”.

3. Remove a blind grommet, make a hole in it and insert the
connecting cable of the under floor heating sensor through it.

4. Remove the jumper located in the flying clamp

5. Connect the cables of the under floor heating sensor to the flying

clamp connected to position C6 on the P.C.B. (in place of the
position previously occupied by the jumper).

6. Bring the grommet back to its initial position, close the lid and
lastly the control panel.

2.10.4. UNDER FLOOR HEATING CONNECTION

2.10.5. REMOTE CONTROL TERMINAL BLOCK,

CYLINDER PROBE AND SECONDARY OUTLET

C5 (1-2)
(red)

C6 (3-11)
(grey)

C7 (1-9)
(violet)

CONNECTIONS TO THE P.CB.

JUMPER:
UNDER FLOOR
HEATING
SENSOR

REMOTE CONTROL

SECONDAR Y OUTLET
(LPG valve,
secondary pump)

2.10.3. ACCESSORY CONNECTION TERMINAL BLOCK

2.10.2. REMOTE

CONTROL CONNECTION

Refer to the illustrations in section 2.10.1.

1. Unscrew the screws “A” and rotate the control panel forwards.

2. Insert the connecting cables of the remote control into the cable

gland “B” and open the lid of the control panel after having
unscrewed the fastening screws “C”.

3. Remove a blind grommet, make a hole in it and pass the
connecting cable of the remote control through it.

4. Connect the cables of the remote control to the flying lead (see
section 2.11.) connected to position C5 on the P.C.B. (positions
with no closed jumper).

5. Bring the grommet back to its initial position, then close the lid
and lastly the control panel.

N

OTE

: The wir ing of the RC must be done by using 2 x 0.5 mm

2

cable
this guarantees a maximum length of 500 m.
The “BUS” cable of the RC must be wired separately from the 230
VAC cable.

NOTE: The wiring of the Outdoor Sensor (SE) must be done by using

2 x 0.5 mm

2

cable this guarantees a maximum length of 50 m.
The sensor must be positioned at least 2 - 2.5 m above the
ground and where possible facing north.The sensor must not
be exposed to direct sunlight.

LEGEND

:

A: JUMPER

When needed, the P.C.B. allows the different options to be selected
by means of a wire link.
The boiler has the following basic arrangement:

1 OPEN
2 CLOSED (jumper)
3 OPEN
4 OPEN
5 OPEN
6 OPEN
7 CLOSED
8 OPEN (MFFI); CLOSED (SYSTEM)

N

OTE

: under absolutely no circumstances must jumpers 2, 7 and 8

be removed. The opening of such contacts will lead to boiler
malfunction.

This is the factory configuration. It is recommended that this set-up
not be changed, unless under the following particular circumstances:
JUMPER 3: if the contact is closed, the Secondary Output (flying

clamp connected to connection C7; positions 1-9)
controls an LPG valve (optional).

JUMPER 4: if the contact is closed, the continuous operation of

the pump is selected. If the contact remains open, it
has no effect and there is no change in the
operation of the boiler.

JUMPER 5: if the contact is closed, the signal transmitted by the

connection of the secondary output clasp
(connected to C7; positions 1-9) relates to a
secondary pump (optional). If the contact remains
open, the output signal controls a zone valve

(optional).
JUMPER 6: not used
JUMPER 7/8:

I = inserted (contact closed)
N.I = not inserted (contact open)

N

OTE: it is essential that the operations involving setting of the

jumpers be carried out only with the device turned off.

10

275

The P.C.B. is fitted with 2 fuses, on the
live and the neutral.
The fuse holder contains:

- 5 x 20mm “3.15A Slow”glass fuses

2.11. ELECTRICAL DIAGRAM

B: Control microprocessor
C: Flame detection jumper (under no circumstances should this

jumper be moved from the 1-2 position)
D: Anti-cycling device (RA)
E: Maximum heating output regulation (PR)
F: Soft-light regulation (RLA)
G: Operating mode selector knob
H: Heating temperature adjustment
I: Domestic hot water temperature adjustment
J: Remote control module
K: Main microprocessor
L: Relay
M: Fuses (2 x 0.54 A SLOW)
N: Transformer (PRI: 230V-50Hz; SEK: 10V-0,8VA; SEK:10V-3,5VA;

SEK:10V-3,5VA;)
O: Fuses (2 x 3.15 A SLOW)
P: Earth
Q: Spark generator
R: Connection to the main P.C.B.
S: Comfort light
T: Programming keys
U: Comfort key
V: Alpha-numeric display
X: Set and reset key
W: Connection to PC

C1 = FAN

1: “Hall” sensor power supply 12V (red)
2: “Hall” sensor ground (blue)
3: Not used
4: Start of coil (black)
5: “Hall” sensor input (white)
6: End of coil (brown)

C2 = POWER SUPPLY

1: Earth (yellow/green)
2: Earth (yellow/green)
3: Not connected
4: Neutral (blue)
5: Not connected
6: Live (brown)

7

N.I.

I.

N.I.

I.

8

N.I.
N.I.

I.
I.

CONFIGURATION

Central heating only
MFFI
Not used
RFFI System

11

275

2.12. WATER CIRCUIT DIAGRAMS

LEGEND:

1- Fan
2 - Main Heat exchanger
3 - Ignition/detection electrode
4 - Burner
5 - Gas valve
6 - Heating return temperature probe
7 - Heating flow temperature probe
8 - Silencer
9 - Motorised valve
10 - Automatic by-pass
11 - Main circuit flow switch
12 - Domestic hot water temperature probe
13 - Secondary heat exchanger
14 - Domestic hot water inlet filter
16 - Drain valve
17 - Safety valve
18 - Pressure gauge
19 - Circulation pump with automatic air release valve
20 - Expansion vessel
21 - Condensate trap inspection cap
22 - Condensate trap
23 - Condensate discharge tube
24 - Condensate trap inlet
25 - Injector
26 - Domestic hot water flow switch

24 MFFI

C3 = CONNECTION TO ROOMSTAT

1: Input - 1
2: Input - 2

C4 = TIMER

1: 3 V output
2: Timer ground
3: Timer output
4: Not connected

C5 = REMOTE CONTROL (Bus+/Bus-)

1: Input/output-1
2: Input/output-2

C6 = SENSOR CONNECTOR

1: Domestic hot water flow switch (grey)
2: Main circuit flow switch (grey)
3: Under floor heating thermostat (grey)
4: Heating flow sensor (grey)
5: Heating return sensor (grey)
6: Domestic hot water sensor (grey)
7: Not used: jumper
8: Outdoor sensor (grey)
9: Domestic hot water flow switch (grey)
10: Main circuit flow switch (grey)
11: Under floor heating thermostat (grey)
12: Flow sensor (grey)
13: Heating sensor (grey)
14: Domestic hot water sensor (grey)
15: Not used: under floor heating
16: Outdoor sensor (grey)

C7 = EQUIPMENT CONNECTIONS

1: Secondary output (optional)
2: Gas valve (white)
3: 3-way valve neutral (white)
4: Pump (white)
5: Ionisation (black)
6: Not connected
7: Ground
8: Pump earth (yellow/green)
9: Secondary output (optional)
10: Gas valve (brown)
11: 3-way valve (domestic hot water) (brown)
12: 3-way valve (heating) (brown)
13: Pump (brown)
14: Not connected
15: Earth
16: Gas valve earth (yellow/green)

12

275

3. COMMISSIONING

3.1. INITIAL PREP ARATION

MTS (GB) Limited support the initiative. Within the
information pack you will find a copy of the logbook. It is
important that this is completed in the presence of your customer,
they are shown how to us it, and it is signed by them.Please instruct
your customer that they must have their logbook with them
whenever they contact a service engineer or us.Preliminary electrical
system checks to ensure electrical safety must be carried out by a
competent person i.e. polarity, earth continuity, resistance to earth
and short circuit.

F

ILLING THE HEATING SYSTEM:

Remove the panels of the case and lower the control panel (see
section 3.2. for further information).
Open the central heating flow and return cocks supplied with the
connection kit.
Unscrew the cap on the automatic air release valve one full turn
and leave open permanently.
Close all air release valves on the central heating system.
Gradually open valve(s) at the filling point (filling-loop) connection
to the central heating system until water is heard to flow, do not
open fully.
Open each air release tap starting with the lower point and close it
only when clear water, free of air, is visible.

Purge the air from the pump by unscrewing the pump plug
and also manually rotate the pump shaft in the direction
indicated by the pump label to ensure the pump is free.

Close the pump plug.
Continue filling the system until at least 1 bar registers on the
pressure gauge.
Inspect the system for water soundness and remedy any leaks
discovered.

F

ILLING OF THE D.H.W. SYSTEM:

Close all hot water draw-off taps.
Open the cold water inlet cock supplied with the connection kit.
Open slowly each draw-off tap and close it only when clear water,
free of bubbles, is visible

G

AS SUPPLY:

Inspect the entire installation including the gas meter, test for
soundness and purge, all as described in BS 6891:1988.
Open the gas cock (supplied with the connection kit) to the
appliance and check the gas connector on the appliance for leaks.

When the installation and filling are completed turn on the central
heating system (sect. 3.4) and r un it until the temperature has
reached the boiler operating temperature.
The system must then be immediately flushed through.
The flushing procedure must be in line with BS 7593:1992 Code of
practice for treatment of water in domestic hot water central heating
systems.
During this operation, we highly recommend the use of a central
heating flushing detergent (Fernox Superfloc or equivalent), whose
function is to dissolve any foreign matter that may be in the system.

Substances different from these could create serious problems
to the pump or other components.

The use of an inhibitor in the system such as Fernox MB-1 or
equivalent is strongly recommended to prevent corrosion (sludge)
damaging the boiler and system.

Failure to carry out this procedure may invalidate the appliance
warranty.

24 RFFI SYSTEM

LEGEND

:

1- Fan
2 - Main Heat exchanger
3 - Ignition/detection electrode
4 - Burner
5 - Gas valve
6 - Heating return temperature probe
7 - Heating flow temperature probe
8 - Silencer
9 - Motorised valve
10 - Automatic by-pass
11 - Main circuit flow switch
12 - Non-return valve (integral to Jig Kit)
13 - Filling loop (integral to Jig Kit)
14 - Indirect cylinder expansion vessel
15 - Expansion relief valve
16 - Drain valve
17 - Safety valve (3 bar)
18 - Pressure gauge
19 - Circulation pump with automatic air release valve
20 - Expansion vessel
21 - Condensate trap inspection cap
22 - Condensate trap
23 - Condensate discharge tube
24 - Condensate trap inlet
25 - Injector

3.3. CONTROL PANEL

A. Selector Knob for Summer/Winter/Flue Test Modes
B. Domestic Hot Water Temperature Adjustment Knob
C. Central Heating Temperature Adjustment Knob
D. On/Off L.E.D.
E. On/Off Knob
F. “COMFORT” Function Push-button/heating only (RFFI SYSTEM)
G. “COMFORT” Function L.E.D./heating only (RFFI SYSTEM)
H. Reset Button
I. Multifunction Display
J. Heating System Pressure Gauge
K. Time Clock
L. Programming “+”key
M. Programming “-” key

When necessary configure the main P.C.B.according to the following
diagram (please refer to the legend on page 17)

I = inserted (contact closed)
N.I = not inserted (contact open)

SECONDARY OUTLET = conntection C7 (position 1-9 page 17)

1. Make sure that:

- the cap of the automatic air release valve is loosened;

- the system pressure is at least 1 bar on the pressure gauge;

3.4. INITIAL START-UP

3.2. REMOVING THE CASING

To disassemble the front casing panel, follow these steps:

1. Unscrew the screws “A” (1/4 turn only) and rotate the control
panel forwards;

2. Unscrew the screws “B”;

3. Unhook the front panel of the casing by lifting it.

To disassemble the side panels, follow these steps:

4. Unscrew the screws “C” (at bottom) fastening the side panels;

5. Lift and unhook the panels.

13

275

A

1

B

2

3

C

4 5

POSITION

3

4

5

INSERTED

Secondary outlet (connection
C7; positions 1-9) controls a
LPG valve (optional).

Continuous pump operation.

Secondary output relates to a
secondary pump (optional).

NOT INSERTED

The secondary outlet
controls what is
selected by Jumper 5.

No change in pump
operation.

Secondary output
controls a zone valve
(optional)

7

N.I.

I.

N.I.

I.

8

N.I.
N.I.

I.
I.

CONFIGURATION

Central heating only
MFFI
Not used
RFFI System

14

275

3.5. DISPLAY:MESSAGES SHOWN DURING

N

ORMAL OPERATION

3.6. OPERATING PARAMETERS

3.6.1. CONTROL

MODES

During operation of the boiler, while it is carrying out its normal
operations, the left-hand display shows a series of characters that
refer to the operations indicated below:

--

Diagnostics phase (precedes the other operations)

00

No request for heat

CC

Heating, burner off

CC..

Heating, burner on

cc

Pump overrun for heating

dd

Domestic hot water, burner off

dd..

Domestic hot water, burner on

hh

Pump overrun for domestic hot water

bb

Storage cylinder, burner off (SYSTEM version)

bb..

Storage cylinder, burner on (SYSTEM version)

N

OTE: the flashing dot on the left-hand display always indicates

“burner off”; if the still dot indicates “burner on”.
The right-hand display (two-digit) shows:

- in HEATING mode: temperature of the heating system flow;

- in DOMESTIC HOT WA TER mode:temperature of domestic hot water.

The boiler has been designed to allow easy intervention with regard
to the operating parameters.

The generation of the set-point and the request for heat are clarified
in the following diagram, with regard to the heating mode.

* See section 3.6.2.
The remote control and the timer are available as an accessory Kit:
in the preceding diagram, it is clear that in the event that a device of
this type is not installed, the calculation of the set-point depends on
an outdoor sensor (if installed) and is carried out by the P.C.B.

N

OTE

: a configuration is also possible which allows for the

simultaneous presence of a remote control and an outdoor sensor.In
this case, the flow temperature is calculated as a function of the
external temperature and the room temperature. In this manner, it is
possible to carry out a particularly efficient modulation, which allows
considerable comfort to be obtained, combined with savings in fuel.
The influence of the roomstat and the timer are shown in the
following diagram, taking into consideration the fact that:

- ON/OFF Room ther mostat installed: contact open or closed,
controlled by the room thermostat temperature sensor.

- ON/OFF Room thermostat not installed: contact closed (jumper).

- Timer installed: contact open or closed, controlled by the timer
settings entered by the user.

- Timer not installed: contact open.

LEFT RIGHT

- the gas cock is closed;

- the electrical connection has been carr ied out in the correct
manner. To allow the air to escape from the system, proceed as
follows:

- turn on the On/off knob “D” and position the selector knob “A” in
the “winter” position. The boiler pump will start up and three
consecutive attempts will be made to ignite the burner. After the
third attempt, the electronic system will shutdown the boiler,
because the supply of gas has been cut off. The message “A01”
will appear on the display;

- let the pump operate until all the air has escaped from the
system;

- repeat the procedure for bleeding the radiators of air;

- draw hot water for a short while;

- check the system pressure and, if it has gone down, fill it with
water until it returns to 1 bar.

2. Check the flue system for products of combustion.

3. Check that any required local ventilation inlets are open.

4. Fill the boiler condensate trap with water.
N.B. In the event of prolonged period of system shutdown,
the condensate trap should be filled before any renewed use.
A shortage of water in the trap is dangerous because it could
possibly lead to a leakage of fumes into the air.

5. Turn on the gas cock and check the seals on the connections,

including the one for the burner, making sure that the meter does
not signal the passage of gas. Check the connections with a soap
solution and eliminate any leaks.

6. Press the reset button “H” for the lighting system; the spark will
light the main burner. If the burner does not light the first time,
repeat the procedure.

The boiler is configured in the factory for the gas type in
question. It is not necessary to regulate the gas type on
installation.
N

OTE: the reference values of the CO

2

are contained in the

T

ECHNICAL INFORMATION

section on page 4.

Schematic representation of the influence exerted by the roomstat
and by the timer on the request for heat and on the calculation of the
set-point (flow temperature of the primary circuit) by means of the
external temperature values:

The type of curve is entered by means of the controls of the display
P.C.B located under the lid of the P.C.B. itself. To access the
programming buttons (+ / -), raise the lid with a screwdriver as shown
in the illustration.

In the event of the chosen curve not being the most suitable for the
type of system, it may be changed (selecting a more appropriate
one) or moved until the desired thermal behaviour is obtained for the
boiler and the system.

15

275

3.6.2. OUTDOOR SENSOR

In the case of the use of an outdoor sensor, the microprocessor­controlled P.C.B. calculates the most suitable flow temperature,
taking into account the external temperature and the type of system.
The microprocessor is capable of doing this because it is possible to
establish a link between the external temperature and the flow
temperature of the heating system water. This link translates into a
"thermal curve".
The type of curve should be chosen in correspondence with the
planned temperature of the system and the nature of the heat loss
present in the building.
The flow temperature directly influences the room temperature,
therefore making reference to the room temperature is equivalent to
indicating variations in the temperature of the building.

-

+

PROCEDURES AND PRACTICAL EXAMPLES

:
If the building is always cold, under all external temperature
conditions (and therefore in all seasons), the steps to take are as
follows:
The curve must be translated parallel to itself, i.e. raising the flow
temperature (and thereby the room temperature) in parity with the
external temperature.

It is possible to carry out this operation by heating temperature knob.
The konb in vertical position set a temperature oh 20°C.Turning the
knob on the right it’s possible to set a higher room temperature.

In this manner, temperatures for the water coming out of the boiler
are set successively higher, which then influence the room
temperature increasing it to the desired settings.

While turning the knob the display shows “d.xx” for few seconds, “xx”
is the room temperature set. Alternatively, it is possible to lower the
output temperature of the boiler if the room temperature is too hot.
It is possible obtain this turning the knob on the left translating lower
the curve.

NB: The last effect achieved by adjusting the thermal curves is to change

the behaviour of the system in relation to the room temperature. If
the curve used has been selected underestimating the thermal
needs of the building, i.e.it is too “low”, it is possible that the building
will not heat up sufficiently (the boiler will arrive to the set-point
before the building reaches the desired temperature); the result is
that the building will feel cold.

100

60

789

6

5

4

3

2

1

20

+20

-20

16

275

The general conditions to follow upon installation are the following:
Warning (see 3.7.2)
* The curves 1,2,3,4,5,6 could be set in the lower temperature;
* The curves 5,6,7,8,9 could be set in the upper temperature;

CURVE 1: under floor heating (radiant panels at ultra-low

temperature).Planned temperature 30/20°C.

CURVE 2-3: under floor heating (radiant panels, low temperature

radiant plate systems).Planned temperature 40/30°C.

If the room temperature is too cold during the
winter (while in spring the temperature is
adequate), it is necessary to enter a steeper
curve. To do this, press the reset button for 5
seconds and then press it repeatedly until the

letter “FF” appears (using the “+” and “-” keys).
In this manner, the curves may be selected
from 1 to 5.

Alternatively, if the building is too warm in the
winter, while the room temperature is
adequate in warmer seasons, it is necessary
to choose a less steep curve, adjusting it in
the same manner as above.

For buildings with standard insulation, materials and exposure, it is recommended initially that the straight line not be moved parallel to itself. If
a timer is installed, it is possible to set different temperatures for daytime and night-time. It is therefore possible to lower the temperature that
the P.C.B. calculates in relation to the values provided by the outdoor sensor by a quantity decided by the user for night-time operation.To do

this, it is necessary to select the night function “uu”, in the following manner:

- press the reset key for 5 seconds;

- press the same key again once to make the “nn” character appear;

- using the programming keys “+” and “-”, select a value from 0 to 12 depending on the amount of night-time lowering of the temperature
desired.

CURVE 4-5: conventional low temperature boilers (cast iron and

aluminum radiators, radiant plate systems). Planned
temperature 60/45°C.

CURVE 6-7: conventional low temperature boilers (cast iron and

aluminum radiators, radiant plate systems). Planned
temperature 75/60°C.

CURVE 8-9: boilers with higher temperatures (radiators, convectors,

fan coils).Planned temperature 90/75°C.

In the opposite situation (in which the building is too hot in spring and
adequately heated in winter), a higher curve (“dd” and “+”) must first
be chosen and then “moved”turning the heating temperature knob.

If the following situation occurs: with low external temperatures (e.g:
winter, -20°C) the building is adequately heated, but with favourable
climatic conditions (e.g: spring, +20°C) it is not sufficiently heated, it is

necessary first to choose a lower curve (“FF” on the display and then “-”)
and then turning the heating temperature knob.

17

275

3.7.2. SETTING THE TEMPERATURE FIELD

Remove the protection of the display using a screwdriver as a lever.
Press the reset button for over 5 seconds. The display will show

“

AA0033

”. On pressing the reset button again the display will change to

“

RR0000

” (R indicates the setting of the field of regulation of the flow
temperature). Using the button “E”, the setting may be changed. It is
possible to choose two fields of regulation of the flow temperature.

“

0000

” signifies that the flow temperature (which may be set by means
of the knob on the front control panel) may be regulated from 30 to
75°C. “

0011

” signifies that the flow temperature (which also may be set
by means of the knob on the front control panel) may be regulated
from 42 to 82 °C.The factory setting is “

0000

”.

The boiler allows the convenience level to be increased in the output
of domestic hot water by means of the “COMFORT” function. This
function keeps the secondary exchanger warm during the periods in
which the boiler is inactive, thereby allowing the initial water drawn to
be at a higher temperature. The function may be activated by
pressing the “H” key on the control panel (see section 3.3.). When
the function is active, a green light comes on, again located on the
control panel.

N

OTE: During the overrun period of the pump, the “COMFORT”

function, if selected, is temporarily deactivated. The L.E.D. light
remains on to indicate that the boiler will return to the “COMFORT”
mode once the pump overrun is terminated.

This function may be activated by pressing the “H” key on the
control panel (see section 3.3.). When the function is active, a green
light comes on, again located on the control panel.This indicates that
the external indirect cylinder is not maintained at the set temperature,
only the anti-frost protection of the indirect cylinder is active. When
the temperature goes below 5°C, the boiler turns itself on and heats
up the indirect cylinder until the temperature goes over 10°C.

H

EATING ONLY KEY:

24 RFFI

3.7. REGULATIONS

To access the areas reserved for the regulation and control, open the
control panel, after having first unscrewed the plastic fastening
screws, and raise the rubber protection stopper for the
potentiometers, as shown in the illustration.

This allows access to the three regulation potentiometers:

1. RA - Ignition delay (anti-cycling device) potentiometer

It is possible to set the ignition delay by adjusting the
potentiometer with a screwdriver. The values that may be
selected range from 0 to 15 min.
The delay has been set at 15 minutes in the factory. The value

D

ISPLAY MESSAGE REFERENCE

3.7.1. P

OTENTIOMETERS

The boiler is designed to monitor some operating variables and
settings by means of the display on the front control panel. Keeping
the reset key pressed for over 10 seconds allows access to the
“readout” function of the main system variables. By pressing the
button repeatedly after that, it is possible to read the following
information in sequence:

Indication on the
left-hand display

UU//11

UU//22

UU//55

UU//FF

UU//tt

PP//AA

PP//--

PP//LL

bb

ll

Value read on right-hand display

Flow temperature of the heating circuit (C°)
Return temperature of the heating circuit (C°)
Domestic hot water output temperature (C°)
Ionisation current (expressed in bT)
Main circuit flow switch
Heating ignition delay (see section 3.6.4. ­expressed in min.x10)
Maximum thermal power for heating (expressed
in a percentage of the difference between the
maximum power allowed by the boiler and the
minimum)
Soft light power (expressed in a percentage of
the difference between the maximum power
allowed by the boiler and the minimum)
Last safety shut-off (see section 3.7.)
Last shutdown (see section 3.7.)

3.6.3. SETTINGS DISPLAY

To return to the normal display, press the “H” reset key repeatedly
until all the sequence of “readout” functions have scrolled through the
display and until one of the “display of normal operations” has
appeared (the message that appears will depend on the current
operating mode of the boiler).

* N

OTE 1: U/1 means that “

uu

”and “11” blink alternately on the display

N

OTE 2: the value 100% appears as “

0000

” on the display

entered may be viewed in the manner described in section 3.6.3.
(the display shows the value with steps of 10).

2. PR - Maximum heating circuit power potentiometer, variable

between the maximum allowed by the boiler and the minimum
(see “T

ECHNICAL INFORMATION” table). The boiler is calibrated in

the factory at 70%.

3. RLA - Soft-light potentiometer, variable between the

maximum power (shown on the display as “

0000

”, i.e. 100%) and

minimum power (shown on the display as “

0011

”, i.e.1%).The boiler
is calibrated in the factory at a value which is suitable for ignition
with any type of gas (approx.70%).
The display shows the value between 100% (“

0000

” on the display)

and 1% (“

0011

”) of this interval. The indications on the display with

regard to the power are shown in the graph:

3.7.3. COMFORT KEY:

24 MFFI

The pump overrun may be varied (after the burner has been tur ned
off). To access this function, it is necessary to press the reset button
for over 5 seconds and then press it repeatedly until the character

“AA”appears on the left-hand display.
The following modes are available:

0011

1 minute of pump overrun

0033

3 minutes of pump overrun

0066

6 minutes of pump overrun

0099

9 minutes of pump overrun

1122

12 minutes of pump overrun

1155

15 minutes of pump overrun

CCOO

24 hours of pump overrun

It is also possible to set a continuous pump operation by closing the
contact of jumper 4 (see section 2.12.).

Safety shutdown:In the event that a safety shutdown occurs, it is
necessary to contact an Authorised Service Centre.

DISPLAY

AA0011

AA0022

AA0033

AA0077

AA1199

AA2200

AA2211

AA2222

AA3333

AA9999

CAUSE

Too many attempts to ignite on starting up
After three attempts at ignition, no increase in DT was
detected
The heating flow temperature exceeds 100°C during
operation
Too many failures to flame in one period during operation
The flame was detected after the gas valve had closed
The flame was detected before the gas valve opened
The flow switch does not close
The flow switch does not open
Problem with the fan
Problem with the electronic monitoring

NOTE: When there is no ignition, check that the gas cock is open.

18

275

3.7.4. PUMP OVERRUN

3.8. BOILER SAFETY SYSTEMS

3.7.6. R

EGULATION MENU TABLE

3.7.5. TEST MODE

Summary of the functions accessed when the RESET button is pushed for 5 seconds.

The boiler is protected from malfunctioning by means of internal
checks by the P.C.B., which brings the boiler to a stop if necessary.
In the event of the boiler being shut off in this manner, a code
appears on the display which refers to the type of shut-off and the
reason behind it.
There are two types of shut-off:

- SAFETY SHUTDOWN :these group of errors (characterised on
the display by the letter “EE”) this situation is automatically
removed as soon as the cause behind it is resolved.

As soon as the origin of the shutdown disappears, the boiler
starts up again and returns to its normal operation.

- SHUTDOWN: (characterised on the display by the letter “AA”), it is
not removed unless a manual intervention is made.
The boiler may return to operation only if reset by means of
pressing the button “H” (see illustration on page 18) located at
the centre of the display.

There follows a list of the shutdown modes and the respective codes
shown on the display.

Shutdown (“AA” type): if such a situation occurs, it is necessary to reset
the boiler using the appropriate key. If this shutdown occurs again, an
Authorised Service Centre should be contacted.

The P.C.B. allows the boiler to be forced to the maximum or minimum
power.
To make the boiler operate at maximum power (100%: 24kW), it is
necessary to turn the selector knob “A” (section 3.3.) and, using a
light pressure, bring it to the < > position.To return the boiler to its
normal function, turn the selector “A” to the summer or winter
position.

N

OTE: To force the boiler to its maximum output it is necessary to

completely rotate the potentiometer for maximum heating output
regulation (PR).