Set Appliance State:

Mains Power Off
CH Demand
Summer/Winter switch set to WINTER (switch pressed in)
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

While the appliance has a CH demand monitor the pump.
The pump should run once the demand has been recognised (this may take up to 15 seconds)
How does the pump behave?