I have a Whirlpool Accubake Oven, Model # WGP_4800 (I cannot read the middle digit) and it keeps beeping randomly and displaying F2 on the screen. I was told that F2 meant a faulty heat sensor, so I purchased a new one and installed it. The oven now heats up to temperature, but then shuts off and still displays F2. It also beeps each time the door is opened and each time an element gets turned on. Any ideas??