Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to AC Volts Set meter to measure AC Volts
Turn Hot Water Tap On
Selector switch to Hot Water
Gain access to PCB (use insulation mat as necessary)
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Measurement:

Allow fan to start .
Measure voltage across the brown (1) and blue (2) leads on connector X3 on the PCB.
After approximately 5 seconds mains voltage should be present
(240 VAC).
Voltage will only be present for approximately 4 seconds.