I had starting having problems out of my heat, as in it wasn't working. The heating and air guy that came out said the heat has a safety switch so that when it gets too hot, the heating coils shut off. It prevents a fire. Question was, why was it getting too hot? He put a voltmeter on it and he was seeing 272 volts going into the unit. For those who don't know, you're only supposed to have 220 volts coming into the house, which is used for big stuff ( like the heater ) and 110 for the outlets. He confirmed this by checking my wall outlets, and those were reading 136. Since this is not dictated by anything in the house, I was told to call the electric company. Turned out the transformer on the pole behind my house was bad and pushing too much power into my house. They said it was a wonder my house had not caught on fire. So a bad transformer in my back yard almost burned down my house. Bad transformer = Decepticon.