biasi M110B.24SM/C, M110B.32SM/C, M110B.24SR/C User guide

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Page 1

Wall hung, fan flue, room sealed, high efficiency gas boiler

Service manual

RIVA ADVANCE HE

Models: G.C. Appl. No.

M110B.24SM/C 47---583---11 M110B.32SM/C 47---583---12 M110B.24SR/C 41---580---07

Leave this manual adjacent to the gas meter

Page 2

Tab l e of co n te n t s

1 Overall information 1..................

1.1 Overall View 1.........................

1.2 Hydraulic diagram 1....................

2 General access and emptying hydraulic

2.1 Nomenclature 2........................

2.2 Body panels 2.........................

2.3 Control panel 2........................

2.4 Access to the sealed chamber 3.........

2.5 Emptying the primary circuit 3...........

2.6 Emptying the d.h.w. circuit 4............

3Diagrams 5...........................

3.1 Wiring diagram

3.2 Wiring diagram M110B.24SR/... 6........

3.3 Circuit voltages 7......................

4Faultfinding 8........................

5 Condensing heat exchanger 10..........

5.1 Function 10.............................

5.2 Removal 10............................

5.3 Cleaning 11............................

6 D.h.w. heat exchanger 12...............

6.1 Function 12.............................

6.2 Removal 12............................

7Pump 13...............................

7.1 Function 13.............................

7.2 Checks 13.............................

7.3 Removal 13............................

8 Three way diverter valve 15.............

8.1 Function 15.............................

8.2 Checks 15.............................

8.3 Removal of the electric actuator 15........

8.4 Removal of the diverter group and its

9 Electronic control/ignition p.c.b. 17......

9.1 Function 17.............................

9.2 Selection and adjustment devices 17......

9.3 Checking the temperature 18.............

9.4 Operation lights 19......................

9.5 Setting the boiler control function modes 19

9.6 Adjustment of maximum useful output

9.7 Reignition frequency setting 20...........

9.8 Combi / C.H. only mode setting 21........

9.9 Checks 22.............................

9.10 Removal of the electronic control p.c.b 22..

9.11 Thermal control in the ”

9.12 Thermal control in the ”

10 Transformer 26.........................

10.1 Removal 26............................

10.2 Check the transformer 26................

11 Gas valve 27...........................

11.1 Function 27.............................

11.2 Description of the parts 27...............

circuits 2.............................

M110B.24SM/... M110B.32SM/... 5.......

internal parts 16.........................

in c.h. mode 20.........................

”mode 24......

”mode 25......

11.3 Adjustment 27..........................

11.4 Checks 28.............................

11.5 Removal of the gas valve 28..............

12 Primary circuit flow switch 30...........

12.1 Function 30.............................

12.2 Checks 30.............................

12.3 Removal 30............................

13 Expansion vessel and

temperature--pressure gauge 31........

13.1 Function 31.............................

13.2 Checks 31.............................

13.3 Removal of the expansion vessel 31.......

13.4 Removal of the temperature ---pressure

gauge 31...............................

14 D.h.w. flow switch, filter and flow limiter 32

14.1 Function 32.............................

14.2 Description and location of parts 32.......

14.3 Checks 32.............................

14.4 Removal of the sensor 32................

14.5 Removal of the flow switch group

and d.h.w. circuit filter 32.................

14.6 Flow limiter 32..........................

15 Temperature probe 34..................

15.1 Function 34.............................

15.2 Checks 34.............................

15.3 Removal of the c.h.Temperature probe 34..

15.4 Removal of the d.h.w.Temperature probe 35

16 By--pass valve 36......................

16.1 Function 36.............................

16.2 Removal 36............................

17 Fan and Air box 37.....................

17.1 Function 37.............................

17.2 Removal of the Air box and the Fan 37.....

18 Ignition and detection electrodes,

burner and spark generator 38..........

18.1 Function 38.............................

18.2 Removal of the Ignition

and detection electrodes 38..............

18.3 Removal of the burner 38................

18.4 Removal of the front insulation panel 39....

18.5 Removal of the rear insulation 39..........

18.6 Removal of the spark generator 40........

18.7 Checks 40.............................

19 Safety thermostat 42...................

19.1 Function 42.............................

19.2 Checks 42.............................

19.3 Removal 42............................

20 Flue temperature probe NTC

and Safety thermal fuse 43..............

20.1 Function 43.............................

20.2 Removal 43............................

20.3 Checks 43.............................

21 Condensate trap 45....................

21.1 Function 45.............................

21.2 Check the cleanness of the trap 45........

21.3 Removal 45............................

22 Short spare parts list 46................

Page 3

1 Overall information

1.1 Overall View

Flue temperature probe NTC

Condensing heat exchanger air purger valve

Burner

Detection electrode

Air box

Safety thermostat

Fan

Air hose

Diverter valve

Codensate trap

C.h. temp. probe

Main circuit flow switch

D.h.w. temp . probe

Safety thermal

fuse

Condensing

heat exchanger

Ignition electrodes

Spark

Generator

Transfor mer

Gas restrictor

C.h. pressure

relief valve

Automatic

air purger

valve

D.h.w. Flow

Switch

Pump

Gas valve

Control

panel

D.h.w.

heat exchanger

Expansion

vessel

Condensate

trap

1.2 Hydraulic diagram

Central heating (c.h.) operation

Domestic hot water (d.h.w.) operation

C.h.

water return

C.h.

water flow

D.h.w.

inlet

D.h.w.

outlet

Page 4

2 General access and emptying

hydraulic circuits

2.1 Nomenclature

Fig. 2.2

To remove the side panels loosen the screws B and C

(Fig. 2.3), bring the base of the panels away from the boiler and lift them, freeing them from the top hooks.

Fig. 2.1

1 Right side panel

2 Front panel

3 Control panel lid

4 Control panel cover

5 Service panel

6 Left side panel

2.2 Body panels

Warning: isolate the boiler from the mains electricity supply before removing any covering or component.

For the most part of the check and maintenance operations it is necessary to remove one or more panels of the case.

The side panels can be removed only after the removal of the front panel.

To remove the front panel remove screws A (Fig. 2.2), lift the panel and remove it.

Fig. 2.3 --- bottom view of the boiler

2.3 Control panel

Warning: isolate the boiler from the mains electricity supply before removing any covering or component.

To gain access to the parts located inside the control panel proceed as follows:

1 Remove the front panel of the case. 2 Loosen the screws B and C (Fig. 2.3). 3RemovethescrewsD. 4 Move the lower part of the side panels as indi-

cated in Fig. 2.4 and pull the control panel. When completely pulled out, the panel can rotate 45˚ downwards to facilitate the service operations on the internal parts.

Page 5

Fig. 2.4

5RemovethescrewsE and remove the service

panel (Fig. 2.5).

General access and emptying hydraulic circuits

To gain access to the parts contained in the sealed chamber it is necessary to remove the lid of the s ealed chamber.

For this purpose, remove the front and side panels of the case, remove the screws G as indicated in Fig. 2.6 and remove the lid.

2.5 Emptying the primary circuit

1 Close the c.h. circuit flow and return cocks H.

(Fig. 2.7).

Fig. 2.5

6RemovethescrewsF andremovethecontrol

panel lid (Fig. 2.5).

2.4 Access to the sealed chamber

Fig. 2.7 --- bottom view of the boiler

2 Remove the front and right panels of the boiler.

3 Open the drain tap I (Fig. 2.9 combi or Fig. 2.10

only c.h.) until the boiler is completely emptied.

4 To help t he draining of the primary circuit loose

the condensing heat exchanger air purger valve J (Fig. 2.8).

Fig. 2.6

Fig. 2.8

Attention: some water could remain in the condensing heat exchanger.

5 Close drain tap once the emptying has been

completed.

Page 6

General access and emptying hydraulic circuits

Fig. 2.9

Fig. 2.10

2.6 Emptying the d.h.w. circuit

6 Close the d.c.w. inlet cock K (Fig. 2.7). 7 Open one or more hot water taps until the boiler

has been completely emptied.

Page 7

3 Diagrams

3.1 Wiring diagram

M110B.24SM/... M110B.32SM/...

Electric supply

terminal block

External controls

terminal block

gnye

bkbu

Three way

diverter valve

Gas valve

bu bn bu

gnye

123

Pump

gnye bu

rdbkwh

D.h.w. temperature

probe NTC

C.h. temperature

probe NTC

D.h.w. flow

switch

bn bu

bn bk bu

F1F2

X16

whwh

bu bn

LD1LD2LD3

Transfor mer

230V~ / 24V~

bn = brown bu = blue bk = black wh = white rd = r ed gy = grey gn = green ye = yellow vt = violet og = orange gnye = green/yellow rdwh = red/white

Safety

X10X11

X13

rd bk wh

Time switch

rd wh bk

bnbu

X12

bububnbn

gnye

bu bn

Generator

Ignition

electrodes

gnye

X15

bu bn

X24

bn bu

Spark

bu bn

X14

X17

whog

X22

Flame detection

electrode

X23

Fan

LD4

Primary circuit

Flue

flow switch

bkwh

SB1

gybuwh

temperature

probe NTC

Safety

thermal fuse

bk rd

bu bu

COM

thermostat

Page 8

Diagrams

3.2 Wiring diagram

M110B.24SR/...

Electric supply

terminal block

External controls

terminal block

gnye

bn bu

bn bk bu

123

bkbu

Pump

gnye bu

bnbu

bu bn

Gas valve

bu bn bu

gnye

C.h. temperature

probe NTC

F1F2

X16

whwh

bu bn

LD1LD2LD3

Transfor mer

230V~ / 24V~

bn = brown bu = blue bk = black wh = white rd = r ed gy = grey gn = green ye = yellow vt = violet og = orange gnye = green/yellow rdwh = red/white

bububnbn

X12

gnye

bu bn

Generator

Ignition

electrodes

X14

X17

gnye

X24

X15

bu bn

bn bu

X22

X23

bkwh

SB1

gybuwh

Spark

whog

Flame detection

Fan

electrode

temperature

probe NTC

LD4

Primary circuit

Flue

flow switch

bu bu

COM

Safety

thermal fuse

thermostat

X10X11

X13

Safety

Page 9

3.3 Circuit voltages

Diagrams

during c. h. or d.h.w. operation

Electrical voltages with burner on

Pump

230~

Supply network

230~

X12

F1F2

X16

3way

diverter valve

X15

only during c.h. operation

only during d.h.w. operation

D.h.w.

Flow switch

Gas valve

230~

230~ 0230~0

X14

X17

X22

X23

X10X11

X13

230~

LD1LD2LD3

24~

Transfor mer

X24

24=

Fan

SB1

LD4

Main circuit

pressure switch

Safety

thermostat

Page 10

Pressure gauge

--- ---

(7)

Components to check

Safety valve

Expansion vessel

Flue temperature probe NTC

Gas restrictor

Safety thermostat

Detection electrode

Ignition electrode

Spark generator

Fan air restrictor

B y --- p a s s v a l v e

D.h.w. temp . p robe

Main circuit temp. probe

D.h.w. filter

Main circuit flow switch

Gas valve

Boiler settings

Electronic p.c.b.

Fuses (Electronic p.c.b.)

J J J J J

J J J J

J J

D.h.w. flow switch

Diverter valve

Pump

6 7.2 8.2 9.9 11.4 12.2 14.5 15.2 16 17 18.7 18.7 19.2 19.2 20.1 ---

(4)

21.1 ---

---

(3)

---

(2)

(1)

10 ---

D.h.w. heat exchanger

D.h.w. circuit

C.h. circuit

Condensate drain pipe and trap

Flue pipes

Gas supply line

J J J J J J J J J J

Power supply line

Transfor mer

J J J J J J J J J J J

J J J J

J J J J J

Defect

4 Fault finding

Section of the manual !

(note ref. in brackets)

By pressing the reset push--- button

the boiler turns on and operates cor-

rectly.

By pressing the reset push--- button

the boiler starts the ignition cycle.

The b urner doesn’t light on and the

boiler locks again.

By pressing the reset push--- button

the boiler starts the ignition cycle.

The b urner lights on and the boiler

The boiler does not start either in c/h

or d.h.w. mode.

All the operation lights OFF

Fan still.

The b urner doesn’t light either in c.h.

or d.h.w. mode.

Fan turns.

The b urner doesn’t light either in c.h.

or d.h.w. mode.

Fan doesn’t turn.

The b oiler doesn’t control the d.h.w.

temperature.

Turning the d.h.w. temp. adjustment

knob hasn’t effect on the modulation

of the flame.

The boiler operates correctly on c.h.

The boiler lights for a short while on

c.h.

locks again.

L o c k --- o u t s i g n a l l a m p r e d

Normal operation on d.h.w. function.

OFF

Page 11

---------

(7)

20.119.219.218.718.7171615.214.512.211.49.98.27.26---

Pressure gauge

Safety valve

Expansion vessel

Flue temperature probe NTC

Gas restrictor

Safety thermostat

Detection electrode

Ignition electrode

Spark generator

Fan air restrictor

B y --- p a s s v a l v e

J J

value of the flue gases.

D.h.w. temp . p robe

Main circuit temp. probe

D.h.w. filter

Main circuit flow switch

Gas valve

Components to check

(4)

21.1---

(3)

---

(2)

---

(1)

Boiler settings

Electronic p.c.b.

Fuses (Electronic p.c.b.)

D.h.w. flow switch

Diverter valve

J J J

Pump

D.h.w. heat exchanger

D.h.w. circuit

C.h. circuit

Condensate drain pipe and trap

Flue pipes

Gas supply line

Power supply line

Transfor mer

J J J

(8)

J J J

J J J J J

This reading is a reference value for the gas valve setting.

installation manual for proper values.

circuit and the intervention of the safety thermostat.

5 A j a m m e d b y --- p a s s c o u l d c a u s e t h e o v e r --- h e a t i n g o f t h e m a i n

6 Using the flue analyzer, check the CO

stop valves.

the flue terminal is correctly installed (see clearances) and en-

2 Verify the soundness of the gas supply pipe, the position of

3 C heck for soundness and absence of obstructions. Verify that

sert a flow rate limiter (14.6).

7 Check the pressurization of the expansion vessel. Refer to the

8 d.h.w. pressure too high or flow rate too high. If necessary in-

9 The boiler doesn’t reach the nominal heat input.

sure that exhaust gas is not sucked back by the boiler.

(see also installation manual).

4 C heck for soundness of the circuit and verify its correct filling

Defect

Section of the manual !

(note ref. in brackets)

The boiler does not supply d.h.w.

(cold water from the tap).

Regular operation in c/h mode even

during a drawing off d.h.w.

On c/h mode the temperature of the

main circuit reaches 90qCandthec/h

L o c k --- o u t s i g n a l l a m p r e d

system does not heat.

Incorrect modulation J J J J

Noisy bolier J J J J J J

Poor c.h. / d.h.w. temperature (9) J J J J JFPoor d.h.w. temperature. Regular

operationinc/hmode.

Low d.h.w. flow rate J J J

Water leaks from the safety valve dur-

ing operation on c/h

Water leaks from the safety valve

The boiler operates correctly on

d.h.w. mode.

when the boiler is off.

---

Note

Useful information can be obtained also from the

optical indication given by the appliance oper-

Verify the integrity of supply cable, plug and external fuses.

Check the polarity of line and neutral connection

ation l ights (see section 9.4).

1 Check for 230V~ between line (L) and neutral (N)

Page 12

5 Condensing heat exchanger

5.1 Function

The Condensing heat exchanger A in Fig. 5.1 has the function of transferring heat produced from combustion of the gas and from the flue exhausted gas to the water circulating in it.

Fig. 5.1

By reducing the combustion products temperature, the latent heat of the vapour is transferred to the water circuit, allowing an extra gain of useful heat.

The condensed vapour is then drained through the condensate trap B and the draining pipe C.

IFEI

KLM N

5.2 Removal

Warning: isolate the boiler from the mains electricity supply before removing any covering or component.

1 D isconnect the flue system from the boiler. 2 Remove the fan group (rubber pipe, gas pipe) fol-

lowing the instructions from 1 to 6 in section 17.2.

3 D isconnect the detection electrode connector D,

the ignition electrodes connector E and the earth wire F.

4 D isconnect the fan connector G by pressing the

plastic hook placed on the side of the connector

(Fig. 5.2). 5 Unscrew the nuts H (Fig. 5.2). 6 Remove the fan---burner group I. 7 Empty the primary circuit of the boiler. 8RemovetheclipsJ (Fig. 5.2). 9 Loosen the connection K and slightly move the

pipe L upwards, turn it towards left (Fig. 5.2) and

then move the pipe downwards freeing it from the

Condensing heat exchanger.

Fig. 5.2

10 Loosen the connection M and slightly move the

pipe N upwards, turn it towards left (Fig. 5.2) and then move the pipe downwards freeing it from the Condensing heat exchanger.

Fig. 5.3

Page 13

Condensing heat exchanger

11 Using pliers, remove the spring O moving it

downwards and disconnect the rubber pipe P (Fig. 5.3).

12 Unscrew the screws Q and remove the clamps

(Fig. 5.3).

13 Disconnect the two connectors R by pressing the

plastic hook placed on the side of the connector (Fig. 5.3).

14 Remove the Condensing heat exchanger by

levering it and sliding it forwards.

15 Reassemble the Condensing heat exchanger

carrying out the removal operations in reverse order.

Ensure to tight the nuts H --- Fig. 5.2 firmly

5.3 Cleaning

If there are deposits of dirt on the coil of the Condensing

heat exchanger, clean with a bristle paintbrush and re-

move the dust with a hoover.

Warning: After cleaning or replacement as detailed above, if it deemed necessary to undertake a combustion analysis, refer to

the appropriate chapter Maintenance of the installation instructions manual.

Fig. 5.4

The siliconic gasket S Fig. 5.4 m ust be replaced every 2 years.

Page 14

6 D.h.w. heat exchanger

6.1 Function

The d.h.w heat exchanger A in Fig. 6.1 and Fig. 6.3 allows the instantaneous transfer of heat from the primary hydraulic circuit to the water destined for d. h.w use.

Fig. 6.1

The schematic structure is shown in Fig. 6.2.

Fig. 6.3

5 Remove the pump following the instructions in

section 7.3.

Fig. 6.4

6 Completely unscrew the Allen key screws C

(Fig. 6.4) w hich hold the exchanger to the plastic groups.

7 Move the exchanger towards the rear of the boiler

and extract it.

Reassemble the d.h.w.heat exchanger carrying out the removal operations in the reverse order.

Primary hydraulic circuit

Domestic hot water circuit

Fig. 6.2

6.2 Removal

Warning: isolate the boiler from the mains

electricity supply before removing any

covering or component.

1 Remove the front and right hand side panels of

the case. 2 Empty the primary circuit and the d.h.w circuit of

the boiler. 3 Completely unscrew the A llen key screws B

(Fig. 6.3) which hold the exchanger to the brass

group. 4 Remove the electric actuator following the in-

structions in section 8.3.

Warning: to lubricate the O-- ring gaskets exclusively use a silicone base grease compatible to be in contact with foods and approved by the local water Authorities.

Attention. When reassembling the exchanger be sure to put the off centre location/securing pin indicated in Fig. 6.5 towards the left side of the boiler.

Fig. 6.5

Page 15

7 Pump

7.1 Function

The pump A in Fig. 7.1 and Fig. 7.2 has the function of

making the water in the main circuit circulate through

the main condensing heat exchanger and therefore

through the c.h. system (during the c.h. function) or

through the secondary heat exchanger (during the

d.h.w. function).

n Check that the impeller is integral with the rotor.

With the boiler off remove the front and right hand side case panels, lower the control panel and empty the pri mary circuit.

Remove the pump head by undoing the screws which hold it to the pump body and check that the impeller is firmly joined to the rotor.

7.3 Removal

Warning: isolate the boiler from the mains electricity supply before removing any covering or component.

1 Remove the front and right hand side case pan-

els. 2 Empty the primary circuit of the boiler. 3 Extract and lower the control panel. 4 Disconnect the connector B (Fig. 7.2)(Fig. 7.3). 5 Loosen the connection C,and pull up and turn to

the left the pipe D. 6 C.h. only model remove the fork E and remove

pressure gauge connection F (Fig. 7.3) 7 C.h. only model remove the fork G, loosen the

connection H and remove the pipe I (Fig. 7.3)

Fig. 7.1

7.2 Checks

Warning: isolate the boiler from the mains electricity supply before removing any covering or component.

n Check that the pump is not seized and that the movement of the rotor is not subject to mechanical impediments.

With the boiler off, remove the front panel. Remove the air release plug of the pump and turn the rotor with a screwdriver.

n Check the electrical continuity.

With the boiler off, remove the front panel and disconnect the connector B (Fig. 7.2).

Measure the electrical resistance between the pump supply connections.

Fig. 7.2

Electrical resistance of the windings (at ambient temperature) must be about 230 8.

n Check the absence of starting defects.

With the boiler off remove the front case panel.

Remove the air release plug from the pump. Start the boiler and with a screwdriver, turn the rotor in the direction of the arrow. If there is a defect in starting, the rotor will begin to turn normally only starting it manually.

Fig. 7.3 c.h. only model

8 Remove the locking plate J.

Page 16

Pump

9 Unscrew the two screws K that hold the pump on

theframeandremovethepump.

Reassemble the pump carrying out the removal operations in the reverse order. When reassembling the pump, check the correct location of the O---ring gasket

in the inlet port of the pump that seals the connection between the pump and the plastic group.

Page 17

8 Three way diverter valve

8.1 Function

The diverter valve A (Fig. 8.1) has the function of modifying the hydraulic circuit of the boiler by means of an electric command given by the electronic control p.c.b. in order to send the water that exits the primary heat exchanger towards the c. h. system or towards the d.h.w. heat exchanger.

rd = r ed bk = black wh = white

F i g . 8 . 2 --- D . h . w . m o d e

230 V

Spindle B

not visible

9,4 Kohm

Open circuit

Spindle B

visible

Open circuit

Fig. 8.1

8.2 Checks

n Check the electrical continuity

Fig. 8.2 indicates the relationship between the electric command coming from the electronic control p.c.b. and the positionof the actuator B (brass spindle) when the boiler operates in d.h.w. mode.

Fig. 8.3 indicates the relationship between the electric command coming from the electronic control p.c.b. and the position of the actuator B (brass spindle) when the boiler operates in c.h. mode.

In both figures the relationship between the position of the actuator and the resistance of the motor windings (the motor must be disconnected from the wiring) is also given.

rd = r ed bk = black wh = white

F i g . 8 . 3 --- C . h . m o d e

230 V

9,4 Kohm

8.3 Removal of the electric actuator

Warning: isolate the boiler from the mains

electricity supply before removing any

covering or component.

1 Remove the front case panel. 2 D isconnect the connectors C (Fig. 8.4). 3 Remove the fixing spring D and remove the

actuator E.

Reassemble the actuator carrying out the re -

moval operations in the reverse order.

When reassembling the actuator, refer to Fig. 8.2

--- Fig. 8.3 or to the wiring diagram in section 8.2

for the correct wiring connection.

Page 18

Three way diverter valve

Fig. 8.4

8.4 Removal of the diverter group and its

internal parts

1 Removethefrontandbothsidecasepanels. 2 Empty the primary circuit and the d.h.w. circuit of

the boiler. 3 Remove the electric actuator (see section 8.3). 4 Remove the fixing spring F (Fig. 8.5) and remove

the primary circuit flow switch G. 5 D isconnect both c.h. and d.h.w. temperature

probe, respectively H and I . 6 Unscrew the connector J, the c.h. flow connector

and the d.h.w. outlet connector.

Fig. 8.6 Rear view of the boiler

10 Refer to the exploded view in Fig. 8.7 to remove

the internal parts of the three way diverter valve.

Fig. 8.5

7 Remove the d.h.w. heat exchanger (see section

6.2).

8RemovetheforkK andmoveawaythepipeL

(Fig. 8.6). 9 Unscrew the screw M andremovethediverter

group.

Fig. 8.7

11 Reassemble the diverter group carrying out the

removal operations in the reverse order.

Warning: to lubricate the O-- ring gaskets exclusively use a silicone base grease compatible to be in contact with foods and approved by the local water Authorities.

Page 19

9 Electronic control/ignition p.c.b.

9.1 Function

Inlet Information

On the Electronic control/ignition

p.c.b.......

Function control C.h. temperature adjustment D.h.w. temperature adjustment Boiler reset button

(control panel fascia)

From other boiler devices....

C.h. temperature probe NTC D.h.w. temperature probe NTC D.h.w. flow switch Primary circuit flow switch Flue temperature probe NTC Safety thermal fuse Safety thermostat Flame detection electrode Room thermostat (if fitted) Time switch

Outlet command

Pump Three way diverter valve Gas valve Fan Ignition electrodes Appliance operation lights* L o c k --- o u t s i g n a l l a m p *

*control panel fascia

Fig. 9.1

The fundamental function of the Electronic control/ignition p.c.b. is that of controlling the boiler in relation t o the external needs (i.e. heating the dwelling or heating the water for d. h.w. use) and operating in order to keep the temperature of the hydraulic circuits constant.

This is obviously possible within the useful power and maximum working temperature limits foreseen.

Generally, the Electronic control/ignition p.c.b. receives inlet information coming from the boiler (the sensors) or from the outside (knobs, room thermostat, etc.), processes it and consequently acts with outlet commands on other components of the boiler (Fig. 9.1).

The Electronic control/ignition p.c.b. is also a full sequence ignition device and does a sequence of operations (ignition cycle) which lead to the ignition of the gas at the burner

It checks the presence of the flame during the entire period in which it is activated and supplies the fan regulating its speed.

The Electronic control/ignition p.c.b. has a safety func- tion and any incorrect interventions or tampering can result in conditions of dangerous functioning of the boiler.

The Electronic control/ignition p.c.b. can lock the functioning of the boiler (lock state) and stop its functioning up to the resetting intervention. The lock is signalled by the lighting of the lock--- out signal lamp and the device can be reset only by using the boiler reset button placed on the control panel fascia.

Some components which are connected to the device can activate the lock state. The causes of a lock state could be:

f The intervention of the safety thermostat (over-

heat of the primary circuit).

f The intervention of the flue temperature probe

(overheat of the combustion products).

f A fault on gas supply.

f Faulty ignition (faulty ignition electrodes, their wir-

ing or connection).

f Faulty flame detection (faulty detection electrode,

its wiring or connection).

f Faulty condensate drainage.

f Faulty gas valve (faulty on ---off operators or not

electrically supplied).

f Faulty Electronic control/ignition p.c.b..

Other components like the primary circuit flow switch can temporarily stop the ignition of the burner but allow its ignition when the cause of the intervention has stopped.

Fig. 9. 20 and Fig. 9.21 show the sequence of the operations that are carried out at the start of every ignition cycle and during normal functioning.

9.2 Selection and adjustment devices

On the Electronic control/ignition p.c.b. several selection, adjustment and protection devices are located. (Fig. 9.2).

Some of these devices are directly accessible by the user (function control, temperature adjustment poten-

Page 20

Electronic control/ignition p.c.b.

tiometers etc.) others, like the fuses, are accessible by removing the service panel.

32 6 10

13 1112141719 151618

Fig. 9.2

91 7 84 5

1 x7 connector --- electric supply terminal block and

external controls terminal block. 2 Fuse F1, F2 3,15 A F 3 Fuse F3, 400 mA T 4 x12 connector --- pump and 3way diverter valve 5 x17 connector --- gas valve 6 x14 connector --- external temperature probe

(optional) 7 x9 connector --- safety thermostat, flue t empera-

ture probe NTC, c.h. temperature probe NTC 8 x11 connector --- d.h.w. temperature probe 9 x10 connector --- d.h.w. flow switch 10 x13 connector --- remote control (optional)

11 x2 connector --- timer

12 Lock --- out signal lamp

13 Boiler reset button

14 Function control / C.h. temperature adjustment 15 x22 connector --- fan

16 x24 connector --- transformer

17 D.h.w. temperature adjustment

18 x5 connector --- transformer

19 Appliance operation lights

9.3 Checking the temperature

The Electronic control/ignition p.c.b. makes it possible to separately adjust the c. h. water flow temperature and d.h.w. outlet temperature.

The temperature of the water is converted into an elec tric signal by means of temperature probes. The user, setting the desired temperature with the control panel knobs operates the variable elements (14 and 17 in Fig. 9.2) of the electronic control p.c.b.

If the power requested is lower than 40% of the maximum power output then control is achieved by switching ON the burner at minimum power, then switching OFF (ON/OFF function). If the power requested is higher, then the burner is switched ON at maximum power and will control by modulating to 40% of the maximum power output.

During the c.h. operation (Fig. 9.3), the signal coming from the c.h. temperature probe is compared to the signal given by the control panel through the adjustment

made by the user (knob

). The result of such a com-

parison operates the fan speed thus regulating the gas flow rate and consequently changing the useful output of the boiler.

Fig. 9.3

When the boiler functions in d.h.w. (Fig. 9.4), the signal coming from the d.h.w. temperature probe is compared with the signal given by the control panel through the

adjustment made by the user (knob

Page 21

Electronic control/ignition p.c.b.

With the boiler switched ON ( or )allthelamps (19 in Fig. 9.2) are activated.

The following table gives the relationship between each of the possible lamp combinations and their meaning.

Normally operating boiler (see the p revious table for details)

C.h. operation

D.h.w. operation

Frost protect operation

D.h.w. operation Excessive temperature on primary circuit

Faulty c.h. temperature probe NTC

90 ˚C

Fig. 9.4

Normally, the result of the comparison between these

two signals directly operates the fan speed adjusting

the useful output generated in order to stabilize the

temperature of the exiting water.

If during the d.h.w. mode operation, the temperature of

the primary circuit goes over 90qC, the useful output is

automatically reduced so that the primary circuit can-

not reach excessive temperatures.

The control sequences in

function and in func-

tion are illustrated in detail in sections 9.11 and 9.12.

9.4 Operation lights

The Electronic control/ignition p.c.b. is provided with

three lamps (L.E.D. indicators) 19 in Fig. 9.2 that give

optical information during the operation of the boiler.

The green lamp on the left gives information whether

the boiler is in stand ---by mode or during the normal

operation of the boiler.

The following table gives the relationship betw een the

lamps indication and their meaning.

Faulty d.h.w temperature probe NTC

Faulty primary circuit (no water or absence of flow)

Lack of burner ignition

Safety thermostat lock out

Faulty fan control system

Flue temperature probe NTC lock out

Open flue temperature probe NTC

Faulty external temperature probe NTC

Flame detection error

Lack of power supply or faulty electronic control p.c.b.

Faulty Electronic control/ignition p.c.b.. *

Lamp

OFF

* These conditions are normal only for a short time when the power supply is applied to the boiler.

If permanent they indicate a faulty p.c.b.

Lamp

Flashing lamp, alone

or simultaneously

with an other lamp.

Flashing lamp,

alternate with

another lamp.

A short pulse every 4 seconds

1secondON1secondOFF

Boiler in stand --- by condition. (function control in position).

Anti--- freeze system active.

Boiler ON condition (function control in or position)

9.5 Setting the boiler control function modes

It is possible to select the various boiler control function modes by using the function selector knob A and the D.h.w. temperature control knob B (Fig. 9.5).

On model M110B.24SR/... the knob B is used just for boiler setting and doesn’t affect the boiler functions during the normal operation.

During the function modes setting, the boiler does not operate.

Page 22

Electronic control/ignition p.c.b.

Fig. 9.5

CED

9.6 Adjustment of maximum useful output in

c.h. mode

The following procedure allows the output of the boiler for c.h. to be limited to meet the system requirement. Adjusting the maximum useful output in c.h. mode does not prevent the boiler firing at maximum rate for d.h.w. production.

1 Turn the boiler ON positioning the function selec-

tor knob A as indicated in Fig. 9.6.

Knob position Maximum useful output in c.h. mode

1 5,8 (19 789) 8,2 (27 977)

2 9,0 (30 707) 12,4 (42 307)

3 12,2 (41 625) 16,5 (56 296)

4 15,5 (52 884) 20,7 (70 626)

5 18,7 (63 802) 24,8 (84 614)

6 21,9 (74 720) 29,0 (98 944)

7 25,1 (85 638) 33,1 (112 933)

Tab . 9 . 1

non condensing kW (BTU/h)

M110B.24SM/...

M110B.24SR/...

M110B.32SM/...

Fig. 9.8

5 To memorize the setting keep pressed the reset

button C for about 5 seconds until the lights E briefly blinks simultaneously.

6 To reset the boiler to the normal operation turn it

OFF and ON by the function selector knob A. In any case, the boiler automatically resets to its normal operation after 10 minutes.

Fig. 9.6

2 Keep pressed the reset button C for about 10 sec-

onds until the lock--- out signal lamp D blinks.

3 The lamps E should give the indication as in

Fig. 9. 7 (maximum c.h. useful output adjust-

ment). If not, press the reset button repeatedly to

obtain it.

Where:

Fig. 9.7

Lamp OFF

Lamp ON

At this step it is possible to visualize the current setting by keeping the reset button C pressed for more than 5 seconds. The lamps will flash a number of times corresponding to the setting (Tab. 9.1 and Fig. 9.8).

4 To change the setting turn the knob B on a posi-

tion corresponding to the desired maximum use-

ful output (Tab. 9.1 and Fig. 9.8).

By turning the knob B, the lock ---out signal lamp

D blinks quickly (2 per seconds) indicating that

the setting has changed and must be memo-

rised.

9.7 Reignition frequency setting

It is possible to select the minimum time that must pass between two ignitions of the burner in c.h. function mode.

1 Turn the boiler ON positioning the function selec-

tor knob A as indicated in Fig. 9.9.

Fig. 9.9

2 Keep pressed the reset button C for about 10 sec-

onds until the lock--- out signal lamp D blinks.

3 The lamps E should give the indication as in

Fig. 9. 10 (reignition frequency). If not, press the reset button repeatedly to obtain it.

Where:

Fig. 9.10

At this step it is possible to visualize the current setting by keeping the reset button C pressed for more than 5

Lamp OFF

Lamp ON

Page 23

Electronic control/ignition p.c.b.

seconds. The lamps will flash a number of times corre-

sponding to the setting (Fig. 9.11).

4 To change the setting turn the knob B on a posi-

tion corresponding to the desired delay. By turning the knob B, the lock ---out signal lamp D blinks quickly (2 per seconds) indicating that the setting has changed and must be memorised.

51/2

81/2

Delay (minutes) Setting No.

Fig. 9.11

11/2

5 To memorize the setting keep pressed the reset

button C for about 5 seconds until the lights E briefly blinks simultaneously.

6 To reset the boiler to the normal operation turn it

OFF and ON by the function selector knob A. In any case, the boiler automatically resets to its normal operation after 10 minutes.

Factory setting = 3 minutes

9.8 Combi / C.H. only mode setting

Two different options are available on the Electronic

control/ignition p.c.b. and proper setting must be done

after a replacement of the p.c.b.

1 Remove the front panel of the case.

2 Turn ON the power supply. Lamps E give the in-

dication as in Fig. 9.12.

6 Press the reset button C repeatedly (2 times) until

the lamps E give the indication as in Fig. 9.14 (boiler mode).

Where:

Fig. 9.14

Lamp OFF

Lamp ON

At this step it is possible to visualize the current setting by keeping the reset button C pressed for more than 5 seconds. The lamps E will flash a number of times corresponding to the setting (Fig. 9.15).

M110B.24SR/... 4flashes

M110B.24SM/... M110B.32SM/... 1flash

Fig. 9.15

7 To change the setting turn the knob B on a posi-

tion corresponding to the boiler models (Fig. 9.15). By turning the knob B, the lock--- out signal lamp D blinks quickly (2 per seconds) indicating that the setting has changed and must be memorised.

8 To memorize the setting keep pressed the reset

button C for about 5 seconds until the lights E briefly blinks simultaneously.

9 Press the reset button C once until the lamps E

give the indication as in Fig. 9.16 (boiler mode).

Where:

Fig. 9.12

Lamp OFF

Lamp Flashing

3 Position the function selector A as in NO TAG and

disconnect the C.h. temperature probe.

4 Keep pressed the reset button C for about 10 sec-

onds (Fig. 9.13) until the lock--- out signal lamp D blinks.

5 Connect the c.h.temperature probe.

Fig. 9.13

Where:

Fig. 9.16

Lamp OFF

Lamp ON

It’s now possible to check the current setting by pressing reset button C for more than 5 seconds. The three lamps E will flash a number of times corresponding to the setting as in Fig. 9.17 (once for the combination and four times for system boilers). At this point only the right green light flashes.

M110B.24SR/... 4flashes

M110B.24SM/... M110B.32SM/... 1flash

Fig. 9.17

Page 24

Electronic control/ignition p.c.b.

10 Turn the water control to minimum. Lock--- out

lamp blinks (2 per second) indicating the setting

has changed

11 To change the setting turn the k nob B on a posi-

tion corresponding to the boiler model

(Fig. 9.17).

12 To memorize the setting keep pressed the reset

button C for about 5 seconds until the lights E

briefly blinks simultaneously. At this point only the

right green light flashes.

13 To reset the boiler to the normal operation turn it

OFF and ON by the function selector knob A.

9.9 Checks

n Check that the fuses are complete

If the Electronic control/ignition p.c.b. does not supply any device (pump, fan, etc.) check that the fuses 2 and 3(Fig. 9.2) are complete.

If a fuse has blown replace it with one that has the same characteristics after having identified the reason for failure.

n Lock sequence

Start the boiler until the burner is ignited.

With the burner firing, interrupt the gas supply. The Electronic control/ignition p.c.b. must carry out four complete ignition cycles and then, after about 4 minutes, goes to lock --- out state.

By turning the boiler on and off by means of the function switch the device must not unlock and the burner must not turn on.

9.10 Removal of the electronic control p.c.b

Warning: isolate the boiler from the mains

electricity supply before removing any

covering or component.

When replacing the Electronic control/ignition p.c.b. it is advisable to go throughthe setting modes of the boiler here described in sections 9.5 to 9.7.

The spare electronic control/ignition p.c.b. is set for natural gas. If the boiler is fed with different gas type, go through the Gas conversion operations described in the In-

stallation manual.

If an external temperature probe (optional) is fitted, the coefficient K has also to be set as described in the Commissioning chapter of the installation manual.

1 Gain access to the parts located inside the con-

trol panel as explained in the section 2.3 of this manual.

2 Remove all the wiring connected to the Electronic

control/ignition p.c.b.

. To disconnect the connectors delicately flex t he hook present on one side of each socket.

3 Remove the spindles of the c.h. and d.h.w. tem -

perature adjustment knobs by delicately pulling them with pliers in the direction shown by the arrow in Fig. 9.18

Fig. 9.18

4 Unscrew the four screw s that hold the Electronic

control/ignition p.c.b. on to the control panel.

5 Remove it by lifting its rear edge and freeing it

from any of the wiring.

6 Re---assemble the Electronic control/ignition

p.c.b. following the removal procedures in the reverse order.

Important

When re ---assembling the Electronic control/ignition p.c.b.:

7 It is not necessary to utilise static protections but

it is advisable to ensure that the pcb is handled with care and h eld at the edges and with clean dry hands.

8 Fit the p.c.b. into the control panel by first insert-

ing the front lower edge under the control knob shafts. Lower the rear edge and ensure that no wiring is trapped beneath.

9 Insert the spindles in the control panel knobs until

the notch A (Fig. 9.19) reaches the potentiometer edge. It is not necessary to force them in the knob.

10 While tightening the screws that fix the Electronic

control/ignition p.c.b. on the control panel, keep the p.c.b. towards the control panel fascia mak-

Page 25

Electronic control/ignition p.c.b.

ing sure of the contact between the boiler reset button B and the tab C (Fig. 9.19).

Fig. 9.19

Attention

After installing the Electronic control/ignition p.c.b. :

11 Make sure the c.h. (

) and d.h.w. ( )tem-

perature adjustment knobs can move freely for the complete range. If not, remove the spindle again as described at step 3, turn the knob half a turn and re --- insert the spindle.

12 Make sure that the settings comply with the in-

dications given in section 9.5.

13 Operate the boiler and close the gas inlet cock so

that the boiler goes into the safety lock ---out state. Verify the correct operation of the boiler reset button by pressing and releasing it.

Warning: After cleaning or replacement as detailed above, if it deemed necessary to undertake a combustion analysis, refer to the appropriate chapter Maintenance of the installation instructions manual.

Page 26

Electronic control/ignition p.c.b.

9.11 Thermal control in the ” ”mode

Switch in the function mode

YES

Operation lights

temperature higher than that

circulator on

Is primary circuit

selected?

YES

checks fan rpm

water from the domestic hot

starts fan

Is fan rpm

exact?

Tak i n g

water circuit?

YES

lock memorised?

Main circuit pressure

YES

switch consense?

temperature higher than 110˚C?

circulator off

fan still

YES

Is flue

stop circulator (3min)

Operation lights

cancels lock

starts ignition discharges

Opens gas valve

beginning of ignition period

Is fan rpm

exact?

turns on lock --- out light

Opeartion lights

flame presence?

YES NO

End of ignition

period?

YES

End of wait

period?

YES

flame presence?

closes gas valve

interrupts ignition discharges

memorizes lock

turns on lock --- out light

r e s e t p u s h --- b u t t o n

stops fan

pressed?

YES

beginning of wait period

YES

interrupts ignition discharges

YES

gas valve open

fan runs

Fig. 9.20

safety thermostat or flue

temperature probe lock out?

YES

YESNO

flame presence?

Page 27

9.12 Thermal control in the ” ”mode

Switch in the function mode

Electronic control/ignition p.c.b.

See functioning with the function

control in the mode

(sec. 9.11)

YES

Opeartion lights

Is primary circuit

temperature higher than that

selected?

YES

checks fan rpm

water from the domestic hot

starts fan

Is fan rpm

exact?

Tak i n g

water circuit?

YES

lock memorised?

Main circuit pressure

YES

circulator on

switch consense?

temperature higher than 110˚C?

Request for heat from

room thermostat?

YES

Is flue

circulator off

fan still

stop circulator (3min)

Operation lights

cancels lock

starts ignition discharges

Opens gas valve

beginning of ignition period

Is fan rpm

exact?

turns on lock --- out light

Opeartion lights

flame presence?

YES NO

End of ignition

period?

YES

End of wait

period?

YES

flame presence?

closes gas valve

interrupts ignition discharges

memorizes lock

turns on lock --- out light

r e s e t p u s h --- b u t t o n

stops fan

pressed?

YES

beginning of wait period

YES

interrupts ignition discharges

YES

gas valve open

fan runs

Fig. 9.21

safety thermostat or flue

temperature probe lock out?

YES

YESNO

flame presence?

Page 28

10 Transformer

10.1 Removal

2 D isconnect the four connectors A. 3 Unscrew the screws B andremovethe

Transformer C by sliding it forward.

4 Reassemble the Transformer carrying out the re-

moval operations in the reverse order.

After reassembling ensure the wires are correctly connected (see Fig. 10.2)

Fig. 10.1

Warning: isolate the boiler from the mains electricity supply before removing any covering or component.

1 Removeallthecasepanelsandthesealed

chamber lid (see section 2).

smaller

connector

smaller

connector

Fig. 10.2

larger

connector

clamp for fitting the transformer

larger

connector

10.2 Check the transformer

Warning: isolate the boiler from the mains electricity supply before removing any covering or component.

1 Remove the Transformer (see section 10.1)

2 Measure the electrical resistance of the primary

and secondary windings. The primary should have a resistance approx. 35 ohm and the secondary approx. 1,4 ohm.

Page 29

11 Gas valve

11.3 Adjustment

11.1 Function

The Gas valve A in Fig. 11.1 controls the gas inflow to the boiler burner.

Fig. 11.1

By means of an electric command given to the on ---off operators the passage of the gas through the Gas valve can be opened or closed.

Warning: isolate the boiler from the mains electricity supply before removing any covering or component.

Check the supply pressure before making any adjustment to the gas valve.

1 Close the gas inlet valve.

2 Remove the front panel of the case and lower the

control panel (see sections 2.2 and 2.3).

3 Loosen the internal screw on the Inlet Pressure

Test Point 5 (Fig. 11.2) of the Gas valve and connect a pressure gauge using a suitable hose.

4 Open the gas inlet valve.

5 Turn on the electricity supply to the boiler, switch-

ing on the fused spur isolation switch. The appliance operation light on the left will flash every 4 seconds.

6 Set the function knobs as illustrated in Fig. 11.4.

7 Open at least one hot water tap fully.

8 Read the inlet pressure value and ensure that it is

within the limits given in the table Gas supply pressures, of the user/installation manual If it does not comply with the required pressure check the gas supply line and governor for faults and/or correct adjustment.

9 Switch off the boilerclose the gas inlet valve and

close the water tap.

10 Disconnect the pressure gauge and close the

Inlet Pressure Test Point 5 (Fig. 11.2).

11.2 Description of the parts (Fig. 11.2)

1 Maximum gas pressure adjustment

2 Minimum gas pressure adjustment

3 On---off operators

4 On --- off operators electric connector

5 Gas valve inlet pressure test point

Fig. 11.2

Gas valve adjustment

11 Fit the probe of the flue analyser in the flue ex-

haust sampling point located on the exhaust pipes of the boiler (Fig. 11.3).

air--- flue exhaust sampling points

Fig. 11.3

12 Turn on the boiler, switching on the fused spur

isolation switch.

13 Open the gas inlet valve.

14 Set the function knob B as indicated in Fig. 11.4.

The appliance operation light on the left will flash every 4 seconds.

Page 30

Gas valve

Fig. 11.4

15 Keep pressed the reset button C for about 10

seconds (Fig. 11.4) until the lock--- out signal lamp D blinks.

16 The lamps E should give the indication as in

Fig. 11.5.

Where:

Fig. 11.5

Lamp OFF

Lamp ON

17 Release and keep the reset button C pressed for

more than 5 seconds until the lock --- out signal lamp D is switched off. The boiler will now go through an ignition sequence and the burner w ill light.

18 Open at least one hot water tap fully.

Adjusting minimum gas valve setting

19 Set the knob F to the minimum position as illus-

trated in Fig. 11.6.

Fig. 11.7

23 Allow the analyser to give a stable reading. 24 Read the CO

%value.

It should be between 9,0 and 9,8 % (natural gas G20) or between 10,0 and 11,0 % (LPG G31). To ad j u s t t h e CO Fig. 11.2) (by rotating it clockwise the CO

% value rotate screw (1 ---

%de-

creases).

25 Switch off the boiler and turn off the hot wat er

tap(s).

26 Close the air---flue sampling points. 27 After adjustment fit the protective brass plug (2,

Fig. 11.2).

Important: after the gas pressure checks and any adjustment operations, all of the test points must be sealed.

11.4 Checks

Warning: isolate the boiler from the mains electricity supply before removing any covering or component.

n Check the on--- off operators coils 1 Remove the front panel of the case. 2 Disconnect the electrical connector 4 (Fig. 11.2). 3 Measure the electrical resistance between the

connector pins of the on--- off operators as illustrated in Fig. 11.8.

Fig. 11.6

20 Allow the analyser to give a stable reading.

21 Read the CO

%value.

It should be between 9,0 and 9,8 % (natural gas G20) or between 10,0 and 11,0 % (LPG G31). To a d j u st t h e C O

% value remove the brass plug

by unscrewing it and rotate the Allen key screw ø 4 mm (2 --- Fig. 11.2) (by rotating it clockwise the

%increases).

Checking the maximum gas valve setting

22 Set the knob F to the maximum position as illus-

trated in Fig. 11.7.

ON---OFF Operator approx. 6 400 8*

ON---OFF Operator approx. 920 8*

* at ambient temperature.

Fig. 11.8

11.5 Removal of the gas valve

Warning: isolate the boiler from the mains electricity supply before removing any covering or component.

1 Remove the front panel of the case as explained

in the section 2.3 of this manual and the sealed chamber lid.

2RemovethescrewG and disconnect the con-

nector H (Fig. 11.9).

Page 31

Gas valve

5 Unscrew the connector K (Fig. 11.9), remove the

fixing fork L and remove the pipe M (Fig. 11.10).

Fig. 11.9

3 Turn off the gas supply and disconnect the gas

isolation cock connector from the inlet port of the gas valve.

4 Using pliers, remove the spring I and the rubber

pipe J (Fig. 11.9).

Fig. 11.10

Fig. 11.11

6 Unscrew the s crews N and remove the valve

(Fig. 11.11).

7 Reassemble the valve carrying out the removal

operations in reverse order.

Before to fit a new valve it is advisable to pre -- set it as hereafter explained.

8 Remove the brass plug and turn the plastic screw

inside it fully clockwise until it stops. Do not overtight.

9 Turn it counter---clockwise 2 and 3/4 turns.

10 Adjustthegasvalveusingtheflueanalyserasde-

scribed in section 11.3.

After any service operation on the components of the gas circuit check all the connections for gas leaks.

Warning: After cleaning or replacement as detailed above, it is deemed necessary to undertake a combustion analysis as detailed in chapter 11.3 section 11.

Page 32

12 Primary circuit flow switch

12.1 Function

The Primary circuit flow switch (A in Fig. 12.1) function is to detect water flow rate through the primary hydraulic circuit of the boiler.

Boiler OFF B oiler ON

Fig. 12.2

n Electrical check

It is possible to verify the general operation of the switch by measuring the electric resistance between the contacts C. and N.O. of the switch.

1 Remove the switch as explained in section

NO TAG.

2 Measure the electrical resistance between the

tabs marked C. and N.O. (Fig. 12.3). The contact must be normally open.

3 Operate the switch by hand and verify that the

contact is now closed.

N.O.

do not use

Fig. 12.3

12.3 Removal

Warning: isolate the boiler from the mains electricity supply before removing any covering or component.

Fig. 12.1

This hydraulic/membrane operated electrical micro--switch device will control the functioning of the ignition control circuit, providing there is an adequate quantity and flow of water in the primary circuit. Any failure of the pump or obstructions in the primary circuit, whilst in either c.h. or d.h.w. modes, will not allow the device to operate.

This device is connected to the electronic control p.c.b. and if, after the pump operates, it does not activate within 20 seconds the control board w ill indicate that a fault condition (see section 9.4 of this manual) has occurred.

12.2 Checks

Warning: isolate the boiler from the mains electricity supply before removing any covering or component.

n Mechanical function

1 Remove the front panel of the case.

2 Start and stop the boiler either in d.h.w. or c.h.

mode.

3 Looking through the switch box verify the position

of the lever B referring to Fig. 12.2.

n Removal of the switch 1 Remove the front panel of the case. 2RemovetheforkC (Fig. 12.4). 3 Open the box and disconnect the switch. 4 Re --- assemble the parts in reverse order of re-

moval. Refer to Fig. 12.3 for the correct wiring connectors on the switch

Removal of the membrane

1 Remove the front and right hand side panels of

the case, turn off the flow and return isolation valves and empty the primary circuit.

2RemovetheforkC that holds the micro---switch

housing D (Fig. 12.4).

Fig. 12.4

Page 33

Primary circuit flow switch

3 Unscrew the four screws E (see Fig. 12.5) open

the hydraulic operator and remove the membrane F.

Fig. 12.5

4 Reassemble the parts in reverse order of removal.

When assembling the membrane, ensure that its concaveside faces towards the actuator plate G and the reference indicated aligns with the seat H (see Fig. 12.5).

13 Expansion vessel and

temperature---pressure gauge

13.1 Function

sion vessel can be changed without removing the boiler.

Warning: isolate the boiler from the mains electricity supply before removing any covering or component.

1 Remove the front and left hand side panels of the

case, turn off the flow and return isolation valves and empty the primary circuit.

2 Completely unscrew the connection K,thelock-

nut L (Fig. 13.2) and remove the expansion vessel from the top of the boiler.

The Expansion vessel (I in Fig. 12.1) function is to allow for the volume expansion of the c.h. circuit water due to the temperature rise.

13.2 Checks

1 Turn off the flow and return isolation valves and

empty the primary circuit of the boiler.

2 Remove the protective cap J (Fig. 13.1) from the

valve on the top of t he expansion vessel and connect a suitable air pressure gauge.

Fig. 13.1

3 Check the pre--- load pressure and refer to the

section Expansion vessel in the User manual and installation instructions for the correct value.

Fig. 13.2

3 Re --- assemble the parts in reverse order of re-

moval.

13.4 Removal of the temperature---pressure

gauge

1 Remove the front and right hand side panels of

the case, turn off the flow and return isolation valves and empty the primary circuit.

2RemovetheforkM and the probe holder spring

N (Fig. 13.3).

3 Squeeze the tabs O to release the temperature ---

pressure gauge P and remove it.

4 Re --- assemble the parts in reverse order of re-

moval.

13.3 Removal of the expansion vessel

If there is at least 400 mm clearance above the boiler and the rear exit flue can be easily removed, the expan-

Fig. 13.3

Page 34

14 D.h.w. flow switch, filter and flow

limiter

14.1 Function

The d.h.w. flow switch A in Fig. 14.1 is a device that generates an electrical signal when hot water is drawn.

Fig. 14.1

Whentheflowratethroughthed.h.w.circuitreaches about 2,5 litres/min’, the float 5 (Fig. 14.3) is dragged upwards and the magnetic in it, getting closer to the sensor 8 closes the electric contact.

Fig. 14.3

14.3 Checks

Warning: isolate the boiler from the mains electricity supply before removing any covering or component.

n Sensor operation 1 Remove the front panel of the case. 2 Measure the electrical resistance at the leads of

the sensor. Without water being drawn, the contact must be open. By opening a hot water tap the contact must be close (electrical resistance zero

8).

14.4 Removal of the sensor

Warning: isolate the boiler from the mains electricity supply before removing any covering or component.

1 Remove the front panel of the case. 2 D isconnect the connectors B and remove the

sensor holder spring C (Fig. 14.2).

3 Remove the sensor.

Fig. 14.2

14.2 Description and location of parts

(Fig. 14.3)

1 Flow switch plug 2 O --- r i n g

3 Flow limiter (M110B.32SM/... optional accessory) 4Body

5Float 6Filter 7 Sensor holder spring

8Sensor

14.5 Removal of the flow switch group and

d.h.w. circuit filter

Warning: isolate the boiler from the mains electricity supply before removing any covering or component.

1 Remove the front panel of the case and empty the

d.h.w. circuit.

2 Remove the sensor (see section 14.4). 3RemovetheforkD andpulluptheflowswitch

plug 1 with the help of a screwdriver.

4 To remove the filter from the flow switch group

separate the filter 6 from the body 4 (Fig. 14.3) by levering it.

5 Reassemble the parts following the removing se-

quence in reverse order.

14.6 Flow limiter

The M110B.24SM/... model is factory fitted with a 10 litre/min. flow limiter.

Page 35

D.h.w. flow switch, filter and flow limiter

If on the M110B.32SM/... model the flow rate of the d.h.w. circuit is too high, it is possible to limit it by installing a flow limiter. The following sizes are available:

Nominal flow rate (litres/min)

Colour

10 Blue

12 Red

14 Pink

To in st a ll t h e f l o w l i m it e r:

1 Remove the flow switch group as explained in the

section 14.5.

2 Separate the flow switch plug 1 from the body 4

levering with a screwdriver one of the two hooks.

Fig. 14.4

3 Insert the flow limiter 3 as shown in Fig. 14.3 4 Reassemble the group following the above se-

quence in reverse order.

Page 36

15 Te m p e r a t u r e pr o b e

15.1 Function

The Temperature probe has the function of converting the temperature of the water in the hydraulic circuit where it is installed into an electrical signal (resistance).

The relation between temperature and electrical resistance is stated in Fig. 15.1.

12500 12000 11500 11000 10500 10000

9500 9000 8500 8000 7500 7000 6500 6000 5500 5000 4500 4000 3500 3000 2500 2000 1500 1000

500

20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100

Fig. 15.1

˚C

15.2 Checks

n Temperature --- resistance relationship

Warning: isolate the boiler from the mains electricity supply before removing any covering or component.

Disconnect the cable from the Temperature probe.

Measure the temperature of the pipe near the Temperature probe and check the electrical resistance according to the graph in Fig. 15.1.

15.3 Removal of the c.h.Temperature probe

Warning: isolate the boiler from the mains electricity supply before removing any covering or component.

1 Removeallthecasepanelsandthesealed

chamber lid.

2 Empty the primary circuit of the boiler. 3 Remove the electric connector C and unscrew

the c.h. Temperature probe A --- F i g . 1 5 . 3 o r Fig. 15.4

4 Reassemble the c.h.Temperature probe carrying

out the removal operations in reverse order.

On the boiler there are two Temperature probes. One on the output of the primary condensing heat exchanger (c. h. Temperature probe) A in Fig. 15.2 and Fig. 15.3; one on the output of the d.h.w. heat exchanger (d.h.w. Temperature probe) B in Fig. 15.2 and Fig. 15.3.

Fig. 15.3

Fig. 15.2

c.h.

return

c.h. flow

d.h.w.

inlet

d.h.w.

outlet

Fig. 15.4

Page 37

Temp e rat ure pro b e

15.4 Removal of the d.h.w.Temperature probe

Warning: isolate the boiler from the mains electricity supply before removing any covering or component.

1 Remove the front panel of the case.

2 Empty the d.h.w circuit of the boiler.

3 Remove the electric connector D and unscrew

the d.h.w. Temperature probe B --- F i g . 1 5 . 3

4 Reassemble the d.h.w. Temperature probe carry-

ing out the removal operations in reverse order.

Warning: to lubricate the O-- ring gaskets exclusively use a silicone base grease compatible to be in contact with foods and approved by the local water Authorities.

Page 38

16 B y --- pa s s v a l v e

16.1 Function

The By---pass valve A in Fig. 16. 1 is located between the c.h. water flow and return and its function is that of guaranteeing a minimum flow across the primary heat exchanger if the circulation across the c.h. system is completely closed.

The By ---pass valve is fitted on the rear side of the diverter group.

2 Empty the primary circuit of the boiler. 3 Remove the diverter group as described in the

section 8.4 of this manual.

4 Unscrew the connector B and remove the by ---

pass valve C (Fig. 16.2) (Fig. 16.3).

Fig. 16.2

Fig. 16.1

16.2 Removal

Warning: isolate the boiler from the mains electricity supply before removing any covering or component.

1 Removeallthecasepanels.

C B

Fig. 16.3

5 Reassemble the by --- pass valve as illustrated in

Fig. 16.2 --- Fig. 16.3 reversing the order of removal.

Page 39

17 Fan and Air box

17.1 Function

The function of the Fan A (Fig. 17.1) is to force the mixture of air and gas into the burner.

The function of the Air box B is to mix the gas and the air in the right proportion.

The flow rate of the air--- gas mixture and consequently the input power of the boiler is proportionalto the speed of the fan that is controlled by the electronic control p.c.b.

3 Disconnect the air manifold C (Fig. 17.2) by pul-

ling it.

Fig. 17.1

17.2 Removal of the Air box and the Fan

Warning: isolate the boiler from the mains electricity supply before removing any covering or component.

1 Turn off the gas supply. 2 Removeallthecasepanelsandthesealed

chamber lid (see section 2).

Fan g asket

Fig. 17.3

4 D isconnect the rubber pipe D (Fig. 17.3).

Fig. 17.4

5 Unscrew the gas connector E (Fig. 17.4)

6 Remove the fixing fork F andremovethegaspipe

G (Fig. 17.3).

7 Loosen without removing the screw H.

8RemovethescrewsI and the air box J.Leavethe

air box with the air manifold clamped to the water pipe.

9 D isconnect the fan connector K by pressing the

plastic hook placed on the side of the connector (Fig. 17.2).

10 Unscrew the screws L (Fig. 17.2). 11 Remove the fan M.

12 Assemble the Fan and the Air box carrying out

the removal operations in reverse sequence.

Fig. 17.2

Before reassembling ensure the fan gasket

(Fig. 17.3) is correctly mounted.

Warning: After cleaning or replacement as detailed above, if it deemed necessary to

undertake a combustion analysis, refer to the appropriate chapter Maintenance of the installation instructions manual.

Page 40

18 Ignition and detection electrodes,

burner and spark generator

18.1 Function

Three electrodes are fitted on the fan --- burner group. Two of them, fitted on the right side of the fan--- burner group A, are the ignition electrodes B and are connected to the spark generator C.

On the left side is the detection electrode D and it detects the presence of the flame.

Fig. 18.2

18.2 Removal of the Ignition and detection

electrodes

Warning: isolate the boiler from the mains electricity supply before removing any covering or component.

1 Removeallthecasepanelsandthesealed

chamber lid (see section 2) .

2 D isconnect the ignition electrodes connector F

and the earth wire G from the spark generator C (Fig. 18. 1) and disconnect the detection electrode connector H.

3 Unscrew the screws I andremovetheignition

electrodes B and the detection electrode D (Fig. 18.1).

4 Assemble the Ignition and detection electrodes

carrying out the removal operation in reverse order.

Fig. 18.1

The burner E is fitted on the rear of the fan ---burner group A.

When reassembling the ignition electrodes be sure to connect correctly the wires to the spark generator (see Fig. 18.3)

earth wire

ignition electrodes

wire

Fig. 18.3

18.3 Removal of the burner

Warning: isolate the boiler from the mains electricity supply before removing any covering or component.

1 Remove the air box and the fan (see section 17.2)

2 Remove the Ignition and detection electrodes

(see section 18.2).

Page 41

Ignition and detection electrodes

3 Unscrew the screws J (Fig. 18.1 )and remove the

cover of the combustion chamber.

4 Unscrew the screws K (Fig. 18.1 ) and remove the

A i r --- g a s d u c t li d .

5 Remove the burner by sliding it forward.

burner gaske

Before reassembling ensure the burner gasket is correctly located.

18.4 Removal of the front insulation panel

See warning note at the end of this chapter before toremovethispart.

1 Remove the Ignition and detection electrodes

(see section 18.2).

2 Remove the burner (see section 18.3).

3Removethe

4 Assemble the new front insulation carrying out

the removal operation in reverse order. When fitting the new panel ensure that the electrodes holes coincide with the holes of the combustion chamber.

front insulation panel (Fig. 18.6).

locating tab

Fig. 18.4

6 Assemble the burner carrying out the removal

operation in reverse order. Ensure the burner is correctly located by lining up the locating tab (Fig. 18.4).

burner gasket

A i r --- g a s d u c t g a s k e t

Fig. 18.5

front insulation

Siliconic gasket

Fig. 18.6

The siliconic gasket (Fig. 18.6) must be replaced if damaged or anyway every 2 years.

The front insulation (Fig. 18.6) must be replaced if damaged or wet

18.5 Removal of the rear insulation

See warning note at the end of this chapter before toremovethispart.

Attention: Cover the inner of the condensing heat exchanger to avoid that dirt and debris fall in the coil.

1 Do the operations of section 18.3 from step 1 to

step 3.

2 Unscrew the screw L, remove the washer M and

the rear insulation N (Fig. 18.7).

Page 42

Ignition and detection electrodes

Fig. 18.7

The rear insulation (Fig. 18.7) must be replaced if damaged or wet

There is not a significant way to verify the integrity of the spark generator.

When the fan turns but the burner does not light a possible cause is a faulty spark generator and it is advisable to replace it to locate the fault.

n Check the position of the electrode edges

Warning: isolate the boiler from the mains electricity supply before removing any covering or component.

1 Remove the ignition electrodes (see section 18.2) 2 Check for the correct distance between the me-

tallic edges of the ignition electrode (see Fig. 18.9

--- Fig. 18.10).

3,5 mm

earth electrode

18.6 Removal of the spark generator

Warning: isolate the boiler from the mains electricity supply before removing any covering or component.

1 Removeallthecasepanelsandthesealed

chamber lid.

2 D isconnect the spark generator connector

coming from the control p.c.b, the electrodes wire and the earth wire coming from the ignition electrodes (Fig. 18.8).

ignition electrodes

wire

earth wire

spark generator

connector

Fig. 18.8

3 Unscrew the screws O and remove the spark

generator

4 Assemble the spark generator carrying out the re-

moval operation in reverse order.

When reassembling the spark generator be sure to connect correctly the wires.

18.7 Checks

n Check of the spark generator

Warning: isolate the boiler from the mains electricity supply before removing any covering or component.

Ignition electrode

Fig. 18.9

n Check the connection wires.

7mm

Ignition electrode

Fig. 18.10

Warning: isolate the boiler from the mains electricity supply before removing any covering or component.

1 Removeallthecasepanelsandthesealed

chamber lid.

Page 43

Ignition and detection electrodes

2 Check for the integrity of the insulation of wires

which connect the electrodes to the spark generator and to the control/ignition p.c.b.

Warning -- Insulation panels material handling care

Mineral fibres are used in this appliance for the insulation panels of the combustion chamber

Excessive exposure to these materials may cause temporary irritation to eyes, skin and respiratory tract.

Known hazards --- Some people can suffer reddening and itching of the skin. Fibre entry into the eye will

cause foreign body irritation, which can cause severe irritation to people wearing contact lenses. Irritation to respiratory tract.

Precautions --- Dust goggles w ill protect eyes. People with a history of skin complaints may be particularly susceptible to irritation. High dust levels are only likely to arise following harsh abrasion. In general, normal handling and use will not present high risk, follow good hygiene practices, wash hands before, touching eyes, consuming food, drinking or using the toilet.

Firstaid---Medicalattentionmustbesoughtfollowing eye contact or prolonged reddening of the skin.

Page 44

19 Safety thermostat

19.1 Function

The safety thermostat A in Fig. 19.1 is a device that senses the temperature of the primary circuit water which flows in the outlet pipe of t he condensing heat exchanger.

If the temperature control system of the boiler fails and the temperature of the primary circuit reaches a dangerous temperature, the safety thermostat opens the electric circuit that supplies the on--- off operators of the gas valve.

Consequently, the full sequence ignition device attempts to light the burner and, at the end, locks the boiler and lights the lock--- out signal lamp.

n Electrical function

1 Removeallthecasepanelsandthelidofthe

sealed chamber.

2 D isconnect the safety thermostat and check its

electrical function. Normally (no intervention) the contact must be closed (electrical resistance zero

8).

19.3 Removal

Warning: isolate the boiler from the mains electricity supply before removing any covering or component.

1 Removeallthecasepanelsandthelidofthe

sealed chamber.

2 Disconnect the wiring B (detail in Fig. 19.2).

3 Unscrew the screws C which hold the overheat

thermostat on the pipe of the condensing heat exchanger and remove it.

Fig. 19.1

19.2 Checks

n Overheat temperature value 1 Set the temperature control knobs to their max.

position and run the boiler in d.h.w. and c.h.

2 Allow the boiler to reach its maximum operating

temperature (monitor the temperature gauge on the instrument panel). The boiler should maintain a temperature below that of the safety thermostat and no overheat intervention should occur.

Warning: isolate the boiler from the mains electricity supply before removing any covering or component.

Fig. 19.2

4 Reassemble the overheat thermostat carrying out

the operations in reverse order.

5 Apply an adequate quantity of heat conducting

compound between the pipe and the thermostat.

Page 45

20 Flue temperature probe NTC and

Safety thermal fuse

20.1 Function

The Flue t emperature probe NTC A in Fig. 20.1 and Fig. 20.2 senses the temperature of the combustion products that flow through the condensing heat exchanger.

NTC and acts as a safety device in extreme case of incorrect operation of the Flue temperature control system.

Reaching the breakdown temperature it opens the circuit and locks out the boiler.

In case of intervention of this safety device the heat ex changer (part shown in Fig. 20.3) may be damaged and must be replaced.

Fig. 20.1

If the temperature of the combustion products circuit reaches the limit temperature, the Flue temperature probe NTC reduces the gas flow rate to the burner. The temperature of the combustion products should decrease to a safe value temperature.

In the case that the temperature of the combustion products reaches a potentially dangerous value, it stops the boiler operation (lock--- out).

This allows the use of plastic materials for the flue outlet pipes and bends.

The use of kits different from the original isn’t however allowed, since the flue pipes are integral parts of the boiler.

Fig. 20.2

ASafetythermalfuse B in Fig. 20.1 --- Fig. 20.2 is also connected in series with the Flue temperature probe

Fig. 20.3

20.2 Removal

Warning: isolate the boiler from the mains electricity supply before removing any covering or component.

1 Removeallthecasepanelsandthesealed

chamber lid.

2 D isconnect the connector C from the Flue tem-

perature probe NTC by pressing the plastic hook placed on the side of the connector.

3 Unscrew and remove the flue temperature probe

A (Fig. 20.2) from the condensing heat exchanger.

4 Assemble the Flue temperature probe NTC carry-

ing out the removal operations in reverse sequence.

20.3 Checks

n Overheat temperature value 1 Set the temperature control knobs to their max.

position and run the boiler in d.h.w. and c.h.

2 Allow the boiler to reach its maximum operating

temperature (monitor the temperature gauge on the instrument panel). The boiler should maintain a temperature below that of the Flue temperature probe NTC and no overheat intervention should occur.

n Temperature --- resistance relationship 1 Remove the Flue temperature probe NTC (see

section 20.2).

2 Measure the Flue temperature probe NTC electri-

cal resistance at the ambient temperature and check it according to the graph in Fig. 20.4

Page 46

Flue thermostat

12500 12000 11500 11000 10500 10000

9500 9000 8500 8000 7500 7000 6500 6000 5500 5000 4500 4000 3500 3000 2500 2000 1500 1000

500

20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100

Fig. 20.4

˚C

Page 47

21 Condensate trap

21.1 Function

21.2 Check the cleanness of the trap

Unscrew the plug on the bottom of the trap and remove dirt eventually deposit.

The condensate trap A in Fig. 21.1 and Fig. 21.2 allows the discharge of the condensate via the condensate drain pipe avoiding in the mean time the escape of combustion products.

A plastic ball closes the trap outlet in case that the trap is empty.

21.3 Removal

Warning: isolate the boiler from the mains electricity supply before removing any covering or component.

1 Remove the front and left case panels. 2 D isconnect the trap from the draining pipe. 3 Using pliers, remove the spring B moving it up-

wards and remove the flexible pipe C. 4 Unscrew the screw D and remove the trap. 5 Unscrew the lock ---nut E and separate the trap

from its bracket. 6 Reassemble carrying out the removal operations

in reverse order.

Fig. 21.1

If the drain pipe is plugged or in any case in which the condensate isn’t correctly evacuated, the condensate level in the trap rises till it reaches the detection electrode in the combustion chamber thus causing the boiler lock---out.

Fig. 21.2

Page 48

22 Short spare parts list

Key G.C. part no. Description Q.ty Manufac-

turer part no.

H 5 8 --- 6 8 8 Burner (mod. M110B.24SM/... M110B.24SR/...) 1 BI1293 100

H 5 8 --- 6 8 9 Burner (mod. M110B.32SM/...) 1 BI1293 101

2 E94 ---576 Expansion vessel 1 BI1182 105 CIMM 7 litres

H 5 8 --- 6 5 9 Condensing heat exchanger (mod.

M110B.24SM/... M110B.24SR/...)

H 5 8 --- 6 6 0 Condensing heat exchanger (mod.

M110B.32SM/...) 4 H 5 8 --- 7 0 2 Fan 1 BI1293 105 EBM RG128 24V 54W

5 H 5 8 --- 6 9 4 Gas valve 1 BI1293 104 SIT 848 Sigma

6 H 5 0 --- 1 8 9 Safety valve 1 BI1181 100 Watts

H 5 8 --- 7 1 7 Electronic regulation p.c.b. (mod.

M110B.24SM/... M110B.24SR/...)

H 5 8 --- 7 1 8 Electronic regulation p.c.b. (mod.

M110B.32SM/...) 8

E01 --- 205 D.h.w. heat exchanger (M110B.24SM/...) 1 BI1001 102

H 0 5 --- 1 6 1 D.h.w. heat exchanger (M110B.32SM/...) 1 BI1161 100

9 H 5 8 --- 6 7 0 Pump 1 BI1911 103

10 H 3 2 --- 5 5 5 Primary circuit flow switch 1 BI1251 501

11 169--- 010 D.h.w. flow switch 1 KI1042 107

12 E00---688 Main. flow switch membrane 1 BI1011 103

13 E83---086 Three way diverter valve (electric actuator) 1 BI1101 102 Elbi

14 E83---101 Overheat thermostat 1 BI1172 105 E L T H --- t y p e 2 6 1

15 H 5 8 --- 6 6 1 Flue temperature probe NTC 1 BI1432 102

16 H 4 4 --- 1 7 0 Fuse 3,15 AF 2 BI1295 108

17 Fuse 400 mA T 1 BI1665 104

18 164--- 026 Temperature probe (main or D.h.w. circuit) 2 KI1001 117

19 H 5 8 --- 7 0 9 Detection electrode 1 BI1293 103

20 H 5 8 --- 6 8 0 Ignition electrode 1 BI1293 102

21 E83---145 Temperature --- pressure gauge 1 BI1475 108 IMIT

1 BI1432 100

1 BI1432 101

1 BI1955 100

1 BI1955 101

Manufacturer’s reference

Orkly (alternative) Bertelli & Partners

Page 49

Short spare parts list

14 16

Page 50

Page 51

Page 52

*1796213402*

17962.1340.2 2008 52A4 UK

14/05

2008

Biasi UK Ltd Newman Park, Western Way Wednesbury, WS10 7BJ Sales Tel No: 0121 506 1340 Sales Fax No: 0121 506 1360 Service Tel No: 0121 506 1350 Service Fax No: 0121 506 1370 www.biasi.co.uk