Yes, I have had exactly the same problem. The front knob have been melting, the grill has been uncontrollable and the Oven cut out after 5 minutes use.
I have fixed the problem by replacing the fan control board References 17676 (PCB-122-4).
Check first if the fan is running running when you switch on either the Oven or the Grill. You may have to remove the oven from your kitchen units, and the fan if working properly it should be spinning at a good rate. If no then it will either be the Fan or the Fan controller board.
To check whether it was the fan or the controller I switched off the main electrical supply, took the blue neutral wire from the fan, disconnected it from the control board, and then wired it directly to the neutral of the main supply. When I restored the power the fan kicked in straight away. We used the oven for a few days with the fan wired in permanently and the Oven and Grill was working as new. I ordered a new controller board off the internet (paid around £20) and this solved all my problems, the oven and the grill operate as they should.
I expect the grill was playing up because it hadn't enough air flow, and the oven was cutting out as it was over heating.
I am no gas engineer, but have years of experience of fixing appliances, as the problem is only electronic you don't need to be a gas engineer to fix this problem. Be careful as it is main supply at 240volts.
Trevor Lock
December 2012
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