Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to AC Volts 
CH Demand
Selector Switch to Hot Water and Heating
CH thermostat to MAX
Gain access to PCB (use insulation mat as necessary)
CH thermostat to MAX
Gain access to PCB (use insulation mat as necessary)
Gas On
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Measure for AC voltage between the black wire at the mains terminal strip that runs from the selector switch to the neutral at the incoming mains.
Expect mains voltage 240vAC.
Note:
On some appliances the incoming terminal strip is located differently and has been rotated through 180° from the one shown.
Expect mains voltage 240vAC.
Note:
On some appliances the incoming terminal strip is located differently and has been rotated through 180° from the one shown.
Isolate as per TOPs P4
and refit as necessary