Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
CH Demand
CH Temperature Selector to MAX
Attach a temperature clamp to the flow pipe as indicated by the red arrow
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Allow boiler to run in CH mode.
The boiler should run on CH until it reaches maximum operating temperature (approximately 85°C).
As it reaches maximum temperature it should modulate then shut down without an overheat fault code shown.
Does the appliance behave as described above?