Set Appliance State:
Mains Power Off
Set Multimeter to AC Volts 
CH Demand
Selector Switch to Hot Water and Heating
CH thermostat to MAX
CH thermostat to MAX
Gas On
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Measure the AC voltage at the black wire on the incoming mains terminal strip that leads to the PCB connector X3 and the incoming neutral.
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