Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Remove the burner

Observation:

Inspect burner for cleanliness and good general condition ensuring there are no cracks etc.
Note:
Upon reassembly check the integrity of any gaskets and seals disturbed and replace as necessary.
While the burner is removed it is worthwhile checking the Ionisation pins as per the safety bulletin.