Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to AC Volts 
Gain access to PCB (use Insulation Mat as required)
Programmer or selector switch set to hot water only
Hot water temperature selector to maximum
Heating temperature selector to OFF
Ensure heat bank is not up to temperature (this can be achieved by running the DHW with the mains power to the appliance on and the gas to the appliance turned off)
Programmer or selector switch set to hot water only
Hot water temperature selector to maximum
Heating temperature selector to OFF
Ensure heat bank is not up to temperature (this can be achieved by running the DHW with the mains power to the appliance on and the gas to the appliance turned off)
Gas On
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Allow fan to run and burner to ignite.
Measure voltage across connection 1 (live, brown wire) and connection 3 (neutral, blue wire) on connector X4 on the main PCB.
Measure voltage across connection 1 (live, brown wire) and connection 3 (neutral, blue wire) on connector X4 on the main PCB.
Isolate as per TOPs P4
and refit as necessary