Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
CH Demand
Remove actuator from the 3-way valve assembly & place in a safe position to observe its operation
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Cancel purge cycle & if required, reset boiler.
Allow the boiler to operate for CH.
Confirm actuator spindle is in the out position (CH).