Set Appliance State:

Turn Hot Water Tap On
Isolate Mains Power to appliance as per TOPs P4
Selector switch to hot water position
CH temperature selector to minimum
DHW temperature selector to maximum
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Does the pump run?
Note:
Do not take sound or vibration as indication pump is running.