Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to DC Volts 
CH Demand
Gain access to PCB (use Insulation Mat as required)
Remove 4 wire connector from fan assembly and make safe
Remove 4 wire connector from fan assembly and make safe
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Reset appliance if required.
(Press and hold the power button for 4 seconds then release)
Measure the DC voltage between pin 3 on connector X20 and an earth (use the copper pipe to the gas valve as earth).
Expect approximately 22V DC or greater.
Is the voltage measured as expected?
(Press and hold the power button for 4 seconds then release)
Measure the DC voltage between pin 3 on connector X20 and an earth (use the copper pipe to the gas valve as earth).
Expect approximately 22V DC or greater.
Is the voltage measured as expected?
Isolate as per TOPs P4
and refit as necessary