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
Gain access to PCB (use Insulation Mat as required)
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Measurement:

Allow fan to start.
Measure for mains voltage across pins 1 & 3 of connector X2.
Expect mains voltage (see note).
Note.
Connector & pin numbers are printed on the PCB.