Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Gain access to PCB (use Insulation Mat as required)
Hot water temperature selector to MAX
Disconnect connector X2 from PCB
Ensure heatbank is not up to temperature (this can be achieved by running the
DHW with the mains power to the appliance on and the gas turned off)
Hot water temperature selector to MAX
Disconnect connector X2 from PCB
Ensure heatbank is not up to temperature (this can be achieved by running the
DHW with the mains power to the appliance on and the gas turned off)
Measurement:
Measure resistance across connection 1 and connection 3 (pink wires) on connector X2 on the main PCB.
Resistance should be short circuit.
Resistance should be short circuit.
Isolate as per TOPs P4
and refit as necessary