Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Remove rear control panel cover to expose main PCB
Disconnect controls interface connector marked H7 on the main PCB

Measurement:

Test 1:
Measure resistance between the live (brown lead) and
neutral (blue lead) connection on the connector.
Test 2:
Measure resistance between the live
(brown lead) and a suitable Earth.
Expected resistance O.L or greater than 1MOhm on both tests.