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

Measurement:

Measure the AC voltage between pin 43 (black)
and pin 44 (black) on connector CN6.
Expect mains voltage.
Note:
Place the probes in the small holes on the PCB.