Set Appliance State:

Mains Power Off
CH Demand
On / Off switch turned to OFF
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Turn On / Off switch ON.
Observe how long it takes for the fault code (fast flash / volatile lockout)
to be displayed after power is restored to the appliance.
Does the fan run before the appliance returns to lockout?
Note.
If a fault code other than volatile lockout is displayed CLICK HERE