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)
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Allow the boiler to fire for DHW.
Measure the AC voltage between pin 5 (brown) and pin 6 (blue) on the 7 pin connector.
Expect mains voltage.
Is the voltage measured as expected?
Measure the AC voltage between pin 5 (brown) and pin 6 (blue) on the 7 pin connector.
Expect mains voltage.
Is the voltage measured as expected?
Isolate as per TOPs P4
and refit as necessary