Set Appliance State:

Mains Power Off
Gas On; Pilot On
CH Demand
Boiler Operating Switch in HW and CH position
Boiler Thermostat calling
WARNING! Mains voltage is expected during test, follow TOPs P4 live testing procedure
Mains Power On

Observation:

After boiler is up to temperature, does the burner go out?
(Maximum CH Flow Temperature is 82 degrees C.)
Note:
It may be necessary to reduce the heating load by turning off some radiators to reduce time taken for this test.