Set Appliance State:

Gas Off
Isolate Mains Power to appliance as per TOPs P4
Remove burner module (Refer to Adapt for guidance)
(place in a safe place)

Observation:

Inspect the combustion chamber for good general condition, flueways are unobstructed and insulation panels are sound.
Note:
1. The burner door seal must be replaced upon reassembly.
2. All disturbed gas connections should be tested for gas tightness.