Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Remove all external controls wiring or the external controls link from the terminal strip and make safe
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Cancel purge cycle.
Does the appliance still try to fire for a CH demand once the purge cycle has been cancelled.