10.2 Fault finding
10.2.1 Central heating
Fig.58
Central heating — Follow operational sequence
Turn on mains power
The display illuminates
20, 28, 40 or 321 flashing
118 flashing
09, 15, 110, 125, 133,
134, 135 or 384 flashing
Set Central Heating
temperature to Maximum.
symbol flashing,
pump runs
Go to section ‘A’
Go to section ‘D’
Ensure all controls and
programmers are calling
for heat
Go to section ‘B’
If 110 is still flashing
go to section ‘H’
YES
NO
NO
NO
NO
NO
NO
NO
Go to section ‘I’
Ensure controls are set to
demand and verify the
contacts are closed
NO
Press the reset button for
1 to 3 seconds
YES
Fan runs after up to
3 minutes
160 flashing
Go to section ‘C’
NO
If 09, 15, 110 or 384 is flashing or re-occurs
regularly, check all PCB connections. If this
has no effect replace the PCB.
Fan runs at correct speed
160 flashing
Go to section ‘C’
Spark at ignition electrodes
up to 5 seconds & for
3 attempts
Go to section ‘F’.
Press the reset button
for 1 to 3 seconds
Burner lights
Go to section ‘E’
Burner goes out after
5 seconds
128 flashing
Go to section ‘G’
NO
109 flashing
125 flashing after 1 min
Go to section ‘J’
110 flashing
NO
Go to section ‘H’
NO
Diverter valve open to
Central Heating circuit
NO
Go to section ‘K’
Burner modulates to
maintain set temperature
Check Heating flow sensor.
Go to section ‘D’
NO
130 flashing
NO
Go to section ‘M’
Burner goes out
NO
Fan stops after 10 seconds
Boiler operation correct
133 flashing
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
PN-0000315
See
Electrical diagram, page 17 for position of terminals and
components.
10 Troubleshooting
57
