Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to AC Volts 
Turn Hot Water Tap On
Gain access to PCB (use Insulation Mat as required)
Boiler On
Boiler On
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Measure the AC voltage between D3 (Brown wire) and D4 (Blue wire) on distribution board.
Alternatively, measure voltage at the pump terminals.
The water pump is receiving power if mains voltage is present.
Alternatively, measure voltage at the pump terminals.
The water pump is receiving power if mains voltage is present.
Isolate as per TOPs P4
and refit as necessary