Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
CH Demand
Attach temperature clamp to flow pipe on right hand side of boiler
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Allow the boiler to ignite and run on central heating operation.
Turn the CH temperature control to the maximum position - approximately 80°C.
If the flow temperature is already at 80°C or above the boiler should either maintain flow temperature or shut down, if flow temperature is below 80°C the boiler should continue to increase flow temperature to approximately 80°C then either maintain the flow temperature or shut down, without overheat occurring.
Note.
To reduce the time taken for this test, reduce the heating circuit by turning off some radiators.