Thank you for that information.
This is caused by poor ventilation. Since this problem just began, and is overheating like that, its really not the valve control that is to blame. It is that this one is need of a professional cleaning, also while they are out there to you they can replace the bad knob.
Its just a common issue with these and they really should be serviced at least once every two years;-)
Any local gas appliance repair technician can do this for you with ease, and it isn't an expensive maintenance job.
In any case, I will stick with you until this is complete.
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Thank you and have a great day!