Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to AC Volts 
Gain access to PCB (use Insulation Mat as required)
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
With power re-instated to the boiler, allow self-check & purge cycle to commence.
Measure for mains voltage across pins 1 & 4 of connector CN2, voltage should be present for approximately 20 seconds then off for 20 seconds repeating, self-check & purge cycle will last approximately 2 minutes (see note).
Note.
Please be aware that there may still be an issue with the display not operating once a diagnosis has been made for the pump not running during self-check & purge cycle.
Measure for mains voltage across pins 1 & 4 of connector CN2, voltage should be present for approximately 20 seconds then off for 20 seconds repeating, self-check & purge cycle will last approximately 2 minutes (see note).
Note.
Please be aware that there may still be an issue with the display not operating once a diagnosis has been made for the pump not running during self-check & purge cycle.
Isolate as per TOPs P4
and refit as necessary