Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
CH Demand
Attach a temperature clamp on the CH flow pipe as near as possible to the appliance (right hand pipe)
Temperature control knob set to MAX (6)
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Allow the boiler to run with a CH demand.
The appliance should run to an operating temperature of approximately 82°C and then the burner should shut down without the overheat stat operating.
Does the boiler operate as described?