Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Remove fan and fan bearing plate (located above the fan)

Observation:

Inspect the condition of the fan bearing plate ensuring the flaps are not stuck, all surfaces are clean, free from corrosion and that the rubber flap is free to lift up from the frame.
Note:
1. Upon reassembly all disturbed joints should be checked for gas tightness.
2. Before reassembly check the integrity of all disturbed gaskets and seals and replace as necessary.
3. Do not apply any type of grease to the frame or rubbers.