Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to AC Volts Set meter to measure AC Volts
CH Demand
Gain access to PCB (use Insulation Mat as required)
CH temperature control set to MAX
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Measurement:

Measure the AC voltage between the 'Enable' terminals
on the interface PCB during the pump purge.
Expect mains voltage.