Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
CH Demand
Attach temperature probe to the flow pipe near to the flow thermistor
CH temperature set to MAX
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Allow boiler to ignite and establish for CH. Run boiler while monitoring the boiler flow temperature.
Does the burner shut down or maintain temperature at approximately 82°C or does overheat occur?
Notes:
To reduce time taken for this test you may wish to turn off some radiators.