Fault code reading:
Remove sound insulation around heater.
Connect test lamp to contacts PHA1 and PHA4.
The heater will now attempt to start and the test lamp will flash rapidly 5 times. The lamp will then flash with a specific number of flashes, indicating the number of the fault codes.
After indicating the fault code, the test lamp will flash rapidly a further 5 times, and then indicate the next fault code. If there is only a single fault code, it will be repeated.
Always check that the fuses have not blown and that the control unit's grounding connection is good (PHA15). The supply voltage should be found on PHA1.
Fault codes:
1 long flash: non-start.
2 Long flashes: flame extinguishes during operation.
3 Long flashes: voltage too low or too high.
4 Long flashes: flame sensor indicates constantly flame too early.
5 Long flashes: flame sensor fault.
6 Long flashes: temperature sensor fault.
7 Long flashes: fuel pump fault.
8 Long flashes: combustion air fan fault.
9 Long flashes: glow plug fault.
10 Long flashes: overheating.