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)
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Press reset to cancel purge cycle countdown.
Allow fan to run.
Measure the voltage across connection 4 (blue wire) and connection 5 (white wire).
Expected voltage 9 volts DC (fan at rest), 5 volts DC (fan running).
Allow fan to run.
Measure the voltage across connection 4 (blue wire) and connection 5 (white wire).
Expected voltage 9 volts DC (fan at rest), 5 volts DC (fan running).
Isolate as per TOPs P4
and refit as necessary