15
F
A
UL
T FINDING CHAR
T P
ar
t 2
Replace control PCB
Can you see the
fl
ame on the burner ?
Replace gas section assembly
Do you feel air
drawing in at the air
Do the gas
solenoïds energise ?
Check that air inlet pipe, ven
-
turi, fan, air/gas pipe or burner
are free of dust and not blocked
Purge the gas pipe and press
on reset button
Does the DHW tem
-
perature rise?
Does the burner still
alight ?
Does the red LED
light and -3 displayed ?
Does the orange
LED light ?
Replace control PCB
Replace DHW
thermistor
Replace control PCB
Replace display PCB or control the
connection between the 2 PCBs
- Adjust the DHW fl
ow rate to
3 l/min at a tap.
- Wait until the temperature
becomes stable.
No
No
No
No
No
Yes
No
No
Does the orange
LED light ?
No
Yes
Replace the DHW heat
exchanger
Yes
Yes
Yes
Yes
No
-3
Replace display PCB or control the
connection between the 2 PCBs
Is the combution
chamber full of conden
-
sates ?
Yes
Check ionisation
probe
No
Ok
Drain and clean combustion cham
-
ber, siphon and drain pipes
Yes
Replace the ionisation probe
No
Stop water draw off
Does DHW temper
-
ature rise over 70
°C ?
Check DHW ther
-
mistor
No
Ok
- Press on DHW key to switch
off DHW mode.
- Press on CH key to switch on
CH mode and set CH tempera
-
ture to maximum.
- Press the RESET button to
cancel the 3 min. delay.
- Ensure that external controls
are calling for heat.
Does the heating
outlet pipe temperature rise
?
Wait until the return pipe
become hot then reduce CH
temperature to minimum
Does the orange
LED light ?
Replace the 3 way valve
Replace control PCB
No
No
The boiler is OK
Yes
Does the heating
outlet pipe temperature
rise ?
Replace the 3 way valve
Yes
-29
No
Yes
Yes
Yes
- Switch off the boiler.
- Draw off DHW at a tap until the
temperature becomes cold.
- Close the tap
- Press on key
28
Does the orange
LED Alight
No
Check the TSS
®
thermistor
Ok
Replace the TSS
®
thermistor
No
25
26
Boiler is OK
Yes
