Set Appliance State:

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

Measurement:

CH temperature set to MAX.
Allow boiler to ignite and establish for CH.
Run boiler up to temperature, does the burner shut down or main 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.