Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to DC Volts 
Gain access to PCB (use Insulation Mat as required)
ON/OFF switch in the ON position
ON/OFF switch in the ON position
Gas On
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
DHW temp selector at approx 35°C.
Turn hot water tap ON.
Measure voltage at PCB connector X2, between pins 6 and 8 (red wires).
Does the voltage reduce as the boiler reaches temperature?
Turn hot water tap ON.
Measure voltage at PCB connector X2, between pins 6 and 8 (red wires).
Does the voltage reduce as the boiler reaches temperature?
Isolate as per TOPs P4
and refit as necessary