Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to AC Volts Set meter to measure AC Volts
DHW Demand
Remove cover from the Pump wiring box.
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Measurement:

Measure the voltage across the live (L) and neutral (N) of the pump.
Is mains voltage measured?
Note: The colour and position of the wires will vary
between systems and components.