Set Appliance State:
Mains Power Off
Set Multimeter to AC Volts 
Turn Hot Water Tap On
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Reset appliance as necessary
Allow burner to ignite and establish
Measure the AC voltage between the Brown and bottom Blue connector at the gas valve as boiler operates. Mains voltage will be present.
Turn Hot Water Tap OFF
(using DHW isolation valve if necessary)
Does the voltage remain after demand ends?
Allow burner to ignite and establish
Measure the AC voltage between the Brown and bottom Blue connector at the gas valve as boiler operates. Mains voltage will be present.
Turn Hot Water Tap OFF
(using DHW isolation valve if necessary)
Does the voltage remain after demand ends?
Isolate as per TOPs P4
and refit as necessary