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)
Disconnect the fan connector from the
fan assembly (place in a safe position)
On-Off switch on
Disconnect the fan connector from the
fan assembly (place in a safe position)
On-Off switch on
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Measure the dc voltage between connector X20 on PCB connection 17(red) and a suitable earth.
Expected voltage approx. 24vdc.
Expected voltage approx. 24vdc.
Isolate as per TOPs P4
and refit as necessary