Set Appliance State:

CH Demand
CH temperature control turned to MAX
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Allow the burner to ignite and run with a CH demand for 1 minute.
Remove the CH demand.
Does the pump continue to run for approximately 12 minutes ?
PUMP OVERRUN OPERATES AS ABOVE
PUMP OVERRUN DOES NOT OPERATE AS ABOVE