Set Appliance State:

Mains Power Off
CH Demand
Selector switch to DHW and CH position
CH temperature selector to maximum
DHW Preheat selector to OFF position
Gas On
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Measurement:

Allow burner to ignite and establish.
Remove heating demand i.e. turn clock to OFF period.
Does pump continue to run for between 1 and 3 minutes?