Biasi RIVA COMPACT HE MK2 M96A.24SR/C User manual

Wall hung, fan flue, room sealed, high efficiency gas boiler
Service manual
RIVA COMPACT HE MK2
Models: G.C. Appl. No.
M96A.24SR/C 41---583---09 System boiler
M96A.28SR/C 41---583---10 System boiler
Leave this manual adjacent to the gas meter

Ta b l e o f c o n t e n t s
1 Overall information 1..................
1.1 Overall View 1.........................
1.2 Hydraulic diagram 1....................
2 General access and emptying
hydraulic circuits 2....................
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...........
3Diagrams 4...........................
3.1 Wiring diagram 4.......................
3.2 Circuit voltages 5......................
4Faultfinding 6........................
5 Primary heat exchanger 8..............
5.1 Function 8.............................
5.2 Removal 8............................
5.3 Cleaning 8............................
6 Condensing heat exchanger 10..........
6.1 Function 10.............................
6.2 Removal 10............................
6.3 Cleaning 10............................
7Pump 12...............................
7.1 Function 12.............................
7.2 Checks 12.............................
7.3 Removal 12............................
8 Electronic control/ignition p.c.b. 14......
8.1 Function 14.............................
8.2 Selection and adjustment devices 14......
8.3 Checking the temperature 15.............
8.4 Operation lights 15......................
8.5 Setting the boiler control function modes 16
8.6 Useful output setting 16..................
8.7 C.H. only mode setting 17................
8.8 Reignition frequency setting 18...........
8.9 Ignition gas pressure adjustment 18.......
8.10 Checks 19.............................
8.11 Removal of the electronic control p.c.b 19..
8.12 Thermal control in the ” ”mode 21......
8.13 Ignition and control sequence 22..........
9 Modulating gas valve 23................
9.1 Function 23.............................
9.2 Nomenclature of the parts (Fig. 2) 23......
9.3 Adjustment 23..........................
9.4 Checks 24.............................
9.5 Removal of the on ---off operators coils 24..
9.6 Removal of the gas valve 24..............
10 Primary circuit flow switch 25...........
10.1 Function 25.............................
10.2 Checks 25.............................
10.3 Removal 25............................
11 Expansion vessel and
temperature -- pressure gauge 26........
11.1 Function 26.............................
11.2 Checks 26.............................
11.3 Removal of the expansion vessel 26.......
11.4 Removal of the temperature---pressure
gauge 26...............................
12 Temperature probe 27..................
12.1 Function 27.............................
12.2 Checks 27.............................
12.3 Removal of the c.h. Temperature probe 27.
13 By--pass valve 28......................
13.1 Function 28.............................
13.2 Removal 28............................
14 Fan and Air pressure sensor 29.........
14.1 Function 29.............................
14.2 Checks 29.............................
14.3 Removal of the Fan 30...................
14.4 Removal of the Air pressure sensor 30.....
15 Ignition and detection electrodes 31.....
15.1 Function 31.............................
15.2 Checks 31.............................
15.3 Removal 31............................
16 Safety thermostat 32...................
16.1 Function 32.............................
16.2 Checks 32.............................
16.3 Removal 32............................
17 Flue temperature probe NTC 33.........
17.1 Function 33.............................
17.2 Checks 33.............................
17.3 Removal 33............................
18 Condensate trap 35....................
18.1 Function 35.............................
18.2 Removal 35............................
19 Short spare parts list 36................

1
1Overall information
1.1 Overall View
Fan
Safety
thermostat
Main heat
exchanger
Burner
Ignition
electrodes
Gas valve
Control
panel
Combustion
chamber
Automatic
air release
Pump
Expansion
vessel
Detection
electrode
valve
Condensing
C.h. temp.
Flue temperature
probe NTC
Primary circuit
heat exchanger
Condensate
trap
pressure switch
Air pressure sensor
probe
B y --- p a s s
valve
C.h. pressure
relief valve
1.2 Hydraulic diagram
Central heating (c.h.) operation
C.h.
water flow
C.h.
water return

2
2General access and emptying
hydraulic circuits
2.1 Nomenclature
2
6
1
54
3
Fig. 1
1 Right side panel
2 Front panel
3 Control panel lid
4 Control panel cover
5Servicepanel
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 oper-
ations it is necessary to remove one or more panels of
the case.
Thesidepanelscanberemovedonlyaftertheremoval
of the front panel.
To remove the front panel remove screws A(Fig. 2), lift
the panel and remove it.
A
Fig. 2
To remove the side panels loosen the screws Band C
(Fig. 3), bring the base of the panels away from the
boiler and lift them, freeing them from the top hooks.
B
D
CB
Fig. 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 Band C(Fig. 3).
3RemovethescrewsD
4 Move the lower part of the side panels as indi-
cated in Fig. 4 and pull the control panel.
When completely pulled out, the panel can rotate
45˚downwards to facilitate the service oper-
ations on the internal parts.

General access and emptying hydraulic circuits
3
Fig. 4
5RemovethescrewsEand remove the service
panel (Fig. 5);
6 To gain access to the electronic regulation PCB
remove the screws Fand remove the control pan-
el lid (Fig. 5);
E
F
F
Fig. 5
2.4 Access to the sealed chamber
G
G
Fig. 6
To gain access to the parts contained in the sealed
chamber it is necessary to remove the lid of the sealed
chamber.
For this purpose, remove the front and side panels of
the case, remove the screws Gas indicated in Fig. 6
and remove the lid.
2.5 Emptying the primary circuit
1 Close the c.h. circuit flow and return cocks H.
(Fig. 7).
H
Fig. 7 --- bottom view of the boiler
2 Remove the front and right panels of the boiler.
3 Open the drain tap I(Fig. 8) until the boiler is com-
pletely emptied.
4 Close drain tap again once the emptying has
been completed.
I
Fig. 8

4
3Diagrams
3.1 Wiring diagram
1
23
L N
gnye bubn
bnbkbu
bn bubn bk bu
bu
bn gnye
bn bu
bn bu
bn
bu
M
~
bu bn gnye
bk
bk
t
wh
wh
tbu
bu
bk
bk
Ignition
electrodes Flame detection
electrode
External controls
terminal block
Electric supply
terminal block
Pump Fan
M
~
Primary circuit
flow switch
Air pressure
sensor
C.h. temperature
probe NTC
Modulating
gas valve
Safety
thermostat
Flue
probe NTC
ye
gy
bn = brown
bu = blue
bk = black
wh = white
rd = red
gy = grey
gn = green
ye = yellow
vt = violet
og = orange
gnye = green/yellow
bubn gnye
bu
bk
bu bu
bn
bu
bk wh wh
rd
rd
P
rd
ye
gy
rd
gy
ye
gy
gy
bk
bk
ye
gy
1
2
3
gnye
1
3
4
bu
* = alternative

Diagrams
5
3.2 Circuit voltages
during c.h. operation
Electrical voltages with burner on
Supply network
230~
230~
Pump
230~
Modulating
Gas valve
Safety
thermostat
0
Fan
230~
+12 V DC
Air
sensor
pressure
0,5 ± 4,5 V DC

6
4Fault finding
Components to check
Section of the manual ! (note ref. in brackets)
---
(1)
---
(2)
---
(3)
18.1 ---
(4)
7.2 8.10 9.4 10.2 12.2 13 14.2 15.2 16.2 17.1 ---
(7)
---
(8)
--- ---
L o c k --- o u t s i g n a l l a m p r e d
Defect #
Power supply line
Gas supply line
Flue pipes
Condensate drain pipe and trap
C.h. circuit
Pump
Fuses (Electronic p.c.b.)
Electronic p.c.b.
Boiler settings
Gas valve (on---off operators)
Gas valve (modulating operator)
Main circuit flow switch
Main circuit temp. probe
B y --- p a s s v a l v e
Fan
Air pressure sensor
Ignition electrode
Detection electrode
Safety thermostat
Flue probe NTC
Injectors
Expansion vessel
Safety valve
Pressure gauge
By pressing the reset push---button the boiler turns on and operates cor- rectly.
J J
(6)
J J J
By pressing the reset push---button the boiler starts the ignition cycle. The burner doesn’t light on, the igni-
tion sparks continue and the boiler locks again.
J J J J J
ON
By pressing the reset push---button the boiler starts the ignition cycle. The burner lights on, the ignition sparks continue and the boiler locks again.
J J J J J J
The boiler does not start either in c/h mode. All the operation lights OFF Fan still.
J J J
The burner doesn’t light either in c.h. mode. Fan turns.
J J J J J
The burner doesn’t light either in c.h. mode. Fan doesn’t turn.
J J J J J J J
OFF
The boiler lights for a short while on c.h..
J J

7
Components to check
Section of the manual ! (note ref. in brackets)
---------
(8)
---
(7)
17.116.215.214.21312.210.29.48.107.2---
(4)
18.1---
(3)
---
(2)
---
(1)
L o c k --- o u t s i g n a l l a m p r e d
Pressure gauge
Safety valve
Expansion vessel
Injectors
Flue probe NTC
Safety thermostat
Detection electrode
Ignition electrode
Air pressure sensor
Fan
B y --- p a s s v a l v e
Main circuit temp. probe
Main circuit flow switch
Gas valve (modulating operator)
Gas valve (on---off operators)
Boiler settings
Electronic p.c.b.
Fuses (Electronic p.c.b.)
Pump
C.h. circuit
Condensate drain pipe and trap
Flue pipes
Gas supply line
Power supply line
Defect #
On c/h mode the temperature of the main circuit reaches 75°Candthec/h
system does not heat.
J
Incorrect modulation J J J Noisy bolier J J
OFF
The boiler operates correctly but the gas pressure to the burner remains at minimum.
J J
---
Water leaks from the safety valve dur- ing operation on c/h
J J J J
---
Water leaks from the safety valve when the boiler is off.
J J J
Note Useful information can be obtained also from the optical indication given by the appliance oper- ation lights (see section 8.4). 1 Check for 230V~ between line (L) and neutral (N)
Verify the integrity of supply cable, plug and external fuses. Check the polarity of line and neutral connection
2 Verify the tightness of the gas supply pipe, the position of stop
valves. Check the gas pressure at the inlet test point of the gas valve (see sect. 9.3) with the boiler at rest and during operation and compare it with the values given on the installation booklet.
3 Check for soundness and absence of obstructions. Verify that
the flue terminal is correctly installed (see clearances) and en- sure that exhaust gas is not sucked back by the boiler.
4 Check for soundness of the circuit and verify its correct filling
(see also installation manual).
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
circuit and the intervention of the safety thermostat.
6Checktheminimum gas pressure at the outlet test point of the
gas valve (see sect. 9.3) and compare it with the value given on the installation booklet.
7 Verify the cleanness of injectors. 8 Check the pressurization of the expansion vessel. Refer to the
installation manual for proper values.

8
5Primary heat exchanger
5.1 Function
The primary heat exchanger Ain Fig. 1 has the function
of transferring heat produced from combustion of the
gas to the water circulating in it.
A
Fig. 1
The hydraulic circuit is composed of 8 elliptical pipes
connected in parallel (Fig. 2).
Fig. 2
5.2 Removal
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
1 Remove the case panels and the sealed chamber
lid (see section 2).
2 Empty the primary circuit of the boiler.
3 Remove the combustion chamber lid Bby un-
screwing the screws C(Fig. 3).
4RemovethescrewsDand the plate E.
5RemovetheclipF
6 Loosen the connection Gand slightly move the
pipe Hupwards.
7RemovetheclipIand the safety thermostat J.It
is not necessary to disconnect it from the wiring.
D
M
C
B
E
C
G
I
J
K
L
H
O
F
N
Fig. 3
8 Loosen the connection Kand move the pipe L
downwards freeing it from the connection of the
primary het exchanger.
9RemovetheclipM
10 Loosen the connection N
11 free the pipe Ofrom the connection of the con-
densing heat exchanger; lift and and rotate it to-
wards right.
12 Remove the heat exchanger by sliding it for-
wards.
13 Reassemble the boiler carrying out the removal
operations in reverse order. Fit the clip Iwith the
arrow pointing upwards as illustrated in Fig. 3.
IMPORTANT -- do not force the connection Gwhen
tighting it.
5.3 Cleaning
If there are deposits of soot or dirt between the blades
of the heat exchanger, clean with a brush or non---me-
tallic bristle brush.
In any case, avoid any actions that can damage the pro-
tective varnish with which the exchanger has been cov-
ered.

Primary heat exchanger
9
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.

Condensing heat exchanger
10
6Condensing heat exchanger
6.1 Function
The return water flows through the condensing heat ex-
changer Ain Fig. 1 and Fig. 2.
By reducing the combustion products temperature, the
latent heat of the vapour is transferred to the water cir-
cuit, allowing an extra gain of useful heat.
The condensed vapour is then drained through the
condensate trap Band the draining pipe C.
A
B
C
Fig. 1
6.2 Removal
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
1 Remove the case panels and the sealed chamber
lid (see section 2).
2 Empty the primary circuit of the boiler.
3RemovethefanDin Fig. 2 (see section 14.3).
4 Disconect the connectors of the flue temperature
probe NTC E
5RemovetheclipF.
6 Completely loosen the connection Gand slightly
move the pipe Hupwards.
7RemovetheclipI.
8 Loosen the connection J
9 Free the pipe Kfrom the connection of the con-
densing heat exchanger; lift and and rotate it to-
wards right.
10 Using pliers, remove the spring Lmoving it to
wards right and disconnect the rubber pipe M.
11 Rotate the exchanger as indicated by the arrow
and remove it towards the front of the boiler.
D
E
G
I
L
M
J
A
K
F
H
Fig. 2
12 Reassemble the exchanger carrying out the re-
moval 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.
After reassembling ensure that the fan -- exchanger
and exchanger-- elbow gaskets are correctly
mounted and ensure a good sealing.
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.
6.3 Cleaning
1 Using pliers, remove the spring Lmoving it to
wards right and disconnect the rubber pipe M
(Fig. 3).
2 Unscrewing the screws N(Fig. 3).
3 Remove the condensing heat exchange lid O
(Fig. 3) moving torwards the front of the boiler.

11
If there are deposits of soot or dirt on the exchanger lid,
cleanwithabrushornon---metallicbristlebrush.
In any case, avoid any actions that can damage the pro-
tective varnish with which the lid has been covered.
L
M
N
O
Fig. 3
4 Reassemble the exchanger carrying out the re-
moval 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.
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.

12
7Pump
7.1 Function
The pump Ain Fig. 1 and Fig. 3 has the function of mak-
ing the water in the main circuit circulate through the
main heat exchanger, the 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).
A
Fig. 1
7.2 Checks
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
nCheck that the pump is not seized and that the
movement of the rotor is not subject to mechanical im-
pediments.
With the boiler off, remove the front panel. Remove the
air release plug of the pump and turn the rotor with a
screwdriver.
nCheck the electrical continuity.
With the boiler off, remove the front panel and discon-
nect the connector B(Fig. 3).
Measure the electrical resistance between the pump
supply connections.
Electrical resistance of the windings (at ambient tem-
perature) must be about 230 Ω
nCheck 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 direc-
tion of the arrow. If there is a defect in starting, the rotor
will begin to turn normally only starting it manually.
nCheck 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 case panels and the sealed chamber
lid (see section 2).
2 Empty the primary circuit of the boiler.
3 Extract and lower the control panel.
4RemovetheclipC(Fig. 2).
5 Loosen the connection D(Fig. 2).
6 free the pipe E(Fig. 2) from the connection of the
condensing heat exchanger; lift and and rotate it
towards right.
C
E
D
Fig. 2
7 Disconnect the connector B (Fig. 3).

Pump
13
B
K
L
A
F
G
H
J
I
Fig. 3
8RemovetheforkFand remove pressure gauge
connection G(Fig. 3)
9RemovetheforkH, loosen the connection Iand
remove the pipe J(Fig. 3)
10 Remove the locking plate K(Fig. 3).
11 Unscrew the two screws Lthat hold the pump on
theframeandremovethepump.
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.
Reassemble the pump carrying out the removal oper-
ations 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 return water group.

14
8Electronic control/ignition p.c.b.
8.1 Function
From other boiler devices....
C.h. temperature probe NTC
Primary circuit pressure switch
Air pressure sensor
Flue temperature probe NTC
Safety thermostat
Flame detection electrode
Room thermostat (if fitted)
On the Electronic control/ignition
p.c.b.......
Function control
C.h. temperature adjustment
Service knob
Boiler reset button
(control panel fascia)
Inlet Information
Pump
On---off operators (gas valve)
Modulation operator (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
Outlet command
Fig. 1
The fundamental function of the Electronic control/igni-
tion p.c.b. is that of controlling the boiler in relation to
the external needs (i.e. heating the dwelling) and oper-
ating 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.), pro-
cesses it and consequently acts with outlet commands
on other components of the boiler (Fig. 1).
The Electronic control/ignition p.c.b. is also a full se-
quence ignition device and does a sequence of oper-
ations (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, supplies the fan and
checks its functioning by means of the signal coming
from the air pressure sensor.
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 func-
tioning 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:
fThe intervention of the safety thermostat (over-
heat of the primary circuit).
fThe intervention of the flue temperature probe
(overheat of the combustion products).
fA fault on gas supply.
fFaulty ignition (faulty ignition electrodes, their wir-
ing or connection).
fFaulty flame detection (faulty detection electrode,
its wiring or connection).
fGas injectors blocked.
fFaulty modulation gas valve (faulty on---off oper-
ators or not electrically supplied).
fFaulty Electronic control/ignition p.c.b..
Other components like the air pressure sensor can tem-
porarily stop the ignition of the burner but allow its igni-
tion when the cause of the intervention has stopped.
Fig. 28 shows the sequence of the operations that are
carried out at the start of every ignition cycle and during
normal functioning.
8.2 Selection and adjustment devices
On the Electronic control/ignition p.c.b. several selec-
tion, adjustment and protection devices are located.
(Fig. 2).
Some of these devices are directly accessible by the
user (function control, temperature adjustment poten-

Electronic control/ignition p.c.b.
15
tiometers etc.) others are accessible by removing the
service panel or the control panel lid.
89101112
14
123 4 5
7
6
13
Fig. 2
1 x1 connector
2 x6 connector
3 x7 connector
4 x4 connector
5 x2 connector
6 x15 connector
7 x11 connector
8 Lock ---out signal lamp
9 Boiler reset button
10 Function control / C.h. temperature adjustment
11 Service knob
12 Appliance operation lights
13 x8 connector
14 Fuse 3,15 A F
8.3 Checking the 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 con-
trol panel knobs operates the variable elements (10 in
Fig. 2) of the electronic control p.c.b.
If the power requested is lower than 40% of the maxi-
mum power output then control is achieved by switch-
ing 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. 3), the signal coming
from the c.h. temperature probe is compared to the sig-
nal given by the control panel through the adjustment
made by the user (knob ). The result of such a com-
parison operates the modulation of the gas valve,
consequently changing the useful output of the boiler.
Fig. 3
The control sequences in function are illustrated in
detail in sections 8.12.
8.4 Operation lights
The Electronic control/ignition p.c.b. is provided with
three lamps (L.E.D. indicators) 12 in Fig. 2 that give op-
tical 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 between the
lamp indication and its meaning.
A short pulse every 4 seconds
Boiler in stand --- by condition.
(function control in
position).
Anti--- freeze system active.
1secondON1secondOFF
Boiler ON condition
(function control in
position)
With the boiler switched ON ( )allthelamps(12in
Fig. 2) are activated.
The following table gives the relationship between each
of the possible lamp combinations and their meaning.

Electronic control/ignition p.c.b.
16
Normally operating boiler
(see the previous table for details)
C.h. operation
Frost protect operation
Faulty c.h. temperature probe NTC
Faulty flue temperature probe NTC
Faulty primary circuit
(no water or low c.h. pressure)
Faulty primary circuit
(absence of flow)
Faulty air pressure sensor
Lack of burner ignition (no ignition signal from
the full seqence ignition device)
Safety thermostat lock out
Flue temperature probe NTC lock out
Flame detection error
Other faults
Lack of power supply or fauly electronic
control p.c.b. *
Lamp
OFF
Lamp
ON
Flashing lamp, alone
or simultaneously
with an other lamp.
Flashing lamp,
alternate with
another lamp.
* 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.
8.5 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
Service knob B (Fig. 4).
During the function modes setting, the boiler does not
operate.
D
FE A
B
Fig. 4
8.6 Useful output setting
To set the useful output proceed as follows:
1 Remove the front panel of the case.
2 Takeoffthelidofthesealedchamber.
3 Switch on the appliance at the mains isolating
spur.
4 Turn the boiler OFF positioning the function selec-
tor A as indicated in Fig. 5.
D
FE AB
Fig. 5
5 Disconnect the electrical connectors C of the C.h.
temperature probe NTC in Fig. 6
C
Fig. 6
6 Keep pressed the reset button D for about 10 sec-
onds until the lock ---out signal lamp E blinks.
7 Connect the the elctrical connectors C of the C.h.
temperature probe NTC in Fig. 6
8 The lamps F should give the indication as in Fig. 7
(useful output, first step). If not, press the reset
button repeatedly to obtain it.
Where: Lamp OFF
Lamp ON
Fig. 7
At this step it is possible to visualize the current setting
by keeping the reset button D pressed for more than 5
seconds. The lamps F will flash a number of times
corresponding to the setting Fig. 8 (once for
M96A.24SR/... , four times for M96A.28SR/...).
B
M96A.24SR/...
1flash
M96A.28SR/...
4flashes
Fig. 8
9 To change the setting turn the knob B on a posi-
tion corresponding to the boiler models (Fig. 8).

Electronic control/ignition p.c.b.
17
By turning the knob B, the lock--- out signal lamp
E blinks quickly (2 per seconds) indicating that
the setting has changed and must be memo-
rised.
10 To memorize the setting keep pressed the reset
button D for about 5 seconds until the lights F
briefly blinks simultaneously.
11 Press the reset button D once until the lamps F
give the indication as in Fig. 9 (useful output, sec-
ond step).
Where: Lamp OFF
Lamp ON
Fig. 9
At this step it is possible to visualize the current setting
by keeping the reset button D pressed for more than 5
seconds. The lamps F will flash a number of times
corresponding to the setting Fig. 10 (once for
M96A.24SR/..., M96A.28SR/...).
B
M96A.24SR/...
M96A.28SR/...
1flash
Fig. 10
12 To change the setting turn the knob B on a posi-
tion corresponding to the boiler model (Fig. 10).
By turning the knob B, the lock--- out signal lamp
E blinks quickly (2 per seconds) indicating that
the setting has changed and must be memo-
rised.
13 To memorize the setting keep pressed the reset
button D for about 5 seconds until the lights F
briefly blinks simultaneously.
14 To reset the boiler to the normal operation turn it
OFF and ON by the function selector knob A.
8.7 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.
3 Position the function selector A as in Fig. 12 and
disconnect the C.h. temperature probe Fig. 6.
Lamps F give the indication as in Fig. 11.
Where: Lamp OFF
Lamp Flashing
Fig. 11
4 Keep pressed the reset button D for about 10 sec-
onds (Fig. 12) until the lock ---out signal lamp E
blinks.
5 Connect the c.h.temperature probe.
D
FE AB
Fig. 12
6 Press the reset button D repeatedly (2 times) until
the lamps F give the indication as in Fig. 13 (boiler
mode).
Where: Lamp OFF
Lamp ON
Fig. 13
At this step it is possible to visualize the current setting
by keeping the reset button D pressed for more than 5
seconds. The lamps F will flash a number of times
corresponding to the setting (Fig. 14).
B
1flash
M96A.24SR/...
M96A.28SR/...
4flashes
Fig. 14
7 To change the setting turn the knob B on a posi-
tion corresponding to the boiler models (Fig. 14).
By turning the knob B, the lock--- out signal lamp
E blinks quickly (2 per seconds) indicating that
the setting has changed and must be memo-
rised.
8 To memorize the setting keep pressed the reset
button D for about 5 seconds until the lights F
briefly blinks simultaneously.
9 Press the reset button D once until the lamps F
give the indication as in Fig. 15 (boiler mode).
Where: Lamp OFF
Lamp ON
Fig. 15
It’s now possible to check the current setting by pres-
sing reset button D for more than 5 seconds. The three
lamps F will flash a number of times corresponding to
the setting as in Fig. 16 (once for the combination and

Electronic control/ignition p.c.b.
18
four times for system boilers). At this point only the right
green light flashes.
B
1flash
M96A.24SR/...
M96A.28SR/...
4flashes
Fig. 16
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 knob B on a posi-
tion corresponding to the boiler model (Fig. 16).
12 To memorize the setting keep pressed the reset
button D for about 5 seconds until the lights F
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.
8.8 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. 17.
D
FE AB
Fig. 17
2 Keep pressed the reset button D for about 10 sec-
onds until the lock ---out signal lamp E blinks.
3 The lamps F should give the indication as in
Fig. 18 (reignition frequency). If not, press the
reset button repeatedly to obtain it.
Where: Lamp OFF
Lamp ON
Fig. 18
At this step it is possible to visualize the current setting
by keeping the reset button D pressed for more than 5
seconds. The lamps F will flash a number of times
corresponding to the setting (Fig. 19).
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
E blinks quickly (2 per seconds) indicating that
the setting has changed and must be memo-
rised.
Setting No.
BDelay (minutes)
1
4
2
35
6
7
0
11/2
3
451/2
7
81/2
Fig. 19
5 To memorize the setting keep pressed the reset
button D for about 5 seconds until the lights F
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 nor-
mal operation after 10 minutes.
Factory setting = 3minutes
8.9 Ignition gas pressure adjustment
1 Turn the boiler OFF.
2 Remove the front panel of the case.
3 Open the gas valve outlet pressure test point (7,
see section 9.2) and connect the gauge.
4 Turn the boiler ON positioning the function selec-
tor knob A as indicated in Fig. 20 (M96A.24SR/...,
M96A.28SR/...) and ensure that the timer selector
switch and room thermostat, if fitted, are set to
“heat demand”.
Run the boiler in c.h. mode.
D
FE AB
Fig. 20
5 Keep pressed the reset button D for about 10 sec-
onds until the lock ---out signal lamp E blinks.
6 The lamps F should give the indication as in
Fig. 21. If not, press the reset button repeatedly
to obtain it.
Where: Lamp OFF
Lamp ON
Fig. 21
7 Keep pressed the reset button D for about 5 sec-
onds until the lock ---out signal lamp E is switched