Set Appliance State:

Mains Power Off
Gas Off
CH Demand
Purge Switch in NORMAL position
HW Switch in OFF position
CH Switch in CH Continuous position
CH Potentiometer set to maximum
WARNING! Mains voltage is expected during test, follow TOPs P4 live testing procedure
Mains Power On

Observation:

Does the CH Pump operate?
Note:
Do not take noise or vibration as a sign of pump operation.