Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Disconnect connector X1 (blue & brown wires) from PCB.

Measurement:

Turn hot tap ON.
Measure resistance across the blue and brown wire at the disconnected connector.
Resistance should be short circuit.
Turn hot tap OFF.
Measure resistance across the blue and brown wire at the disconnected connector.
Resistance should be open circuit.
Reconnect connector after test.