Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Gain access to the incoming connections at the PCB

Observation:

Check that the heating link between 230V OUT "L" and the "LR" with the radiator symbol is present and fitted securely.
Is the link present and correctly fitted?
Note:
The appearance of the white connector may vary depending on the PCB version but this does not affect the test.