8
F
A
UL
T FINDING CHAR
T P
ar
t 1
PLEASE CHECK CAREFULLY FOLLOWING POINTS BEFORE
GOING THROUGH THE FAULT FINDING CHART
-Gas pressure
-Electric mains
-Minimal water pressure in the heating circuit (over 0.8 bar)
- All isolating valves have been opened
- Boiler air vented
-Minimal domestic hot water fl
ow of 2 l/min
Put the selector switch on
I
position
Does the green LED
alight ?
Replace control PCB
Replace control PCB
Replace
diaphragm on 3
way valve motor
Release pump rotor
Replace pump
Replace pressure switch
Does the red LED
alight ?
Does the fan run ?
Check air pressure
switch continuity
between Pand 1
Check voltage on
the fan
Press on reset button
Replace controle PCB
Check or replace the DHW
microswitch
Does the pump run ?
Does the pump run ?
Check DHW fl
ow
switch operation
Check that the
pump spins free
Check voltage in the
pump electrical box
Replace control PCB
Could you hear the
spark generation?
Check air pressure
switch continuity
between P and 2
Replace fan assembly
- Check pressure probes
or
- Check fl
ue duct condition
or
- Replace pressure switch
Yes
Yes
Yes
No
No
No
No
Ok
Ok
Ok
No
Check or replace main or sec
-
ondary heat exchangers. They
could be fully scaled.
Check fl
ow in the
boiler primary circuit
Ok
No
Replace heating thermistor
Check heating
thermistor
Ok
No
No
No
No
No
Yes
Yes
No
No
No
No
Ok
Ok
Ok
Ok
Ok
Turn the DHW selector clock
-
wise to maximum
Does the green LED
DHW mode indication
38
alight?
Yes
Draw of dosmectic hot water
No
Does the pres
-
sure gauge indicate
more than 0.8b
Rise the pressure in the CH
circuit
No
- Check mains electrical
connection
- Check internal fuses
Yes
Yes
Check DHW
command is working
Clean or replace DHW
command
Yes
No
means a test or a choice
means an action
means a group of actions
