The following is a reprint from our Ask the Expert feature on AcmeHowTo.com

Question: I have a Hot Point dryer. When I turn it on the heat turns on for a few minutes and then turns back off and in some cycles won't turn on at all. I have replaced the plug and heating element. I had a sears tech. come out and he told me it was the thermostat. He ordered 3 of them and I installed them and it is still doing the same thing. Can you help?

Answer: I agree with the thermostat diagnosis. If the heat comes on sometimes, then we know the heating element is working. So what makes it go on and off? Three things, the timer control can cycle it, the temperature selection button and the thermostats. The thermostats work like this. There is a hi limit stat that cuts the heat if the dryer gets to the max of the high heat setting. The lo limit stat cuts the heat when the lo limit max is reached and then there is a stat that cuts the heat if the dryer gets too hot and the other stats don't do their job.

If it was the temp button, then some cycles would work and some wouldn't, but it would always do the same thing every time. One exception to this is if the switch is shorting out, it could work sometimes and then stop working. If would be difficult to test because when you tested it, it might appear to be working properly. The vibration or heat of the dryer may make it short out. So this could be the problem. In this same vein, a loose wire or a bad connection could cause this same problem.

The timer control enables a circuit by making a contact. Some dryers have a cycle such as heat for 30 minutes and then air cool for 10 minutes. In this case it would make the circuit for the heating element for 30 minutes and then cut the circuit for the last ten. This control is probably not the problem, but like the switch above, it could be failing or have a bad connection and then it would behave in the same manner.

So bottom line, I'd recheck that you put the right thermostat in the right place, check all the connections, clean any corroded connectors and if still no joy, then try replacing the temp selection switch.