If a dryer vent restriction is completely eliminated, and no heat is being produced, then you must diagnose the problem. When a dryer is not heating, there is a good possibility that the component that does the most work, the heater, is the problem. If you inspect the heater and find out that the resistance wire within the heater is broken, then you have found the problem. Remember in order for that heater to fail, it would have to have the full voltage to it. So don’t make it more complicated and suspect that the timer is defective, or anything like that. It is possible though, that the control thermostat is stuck and the heater has been cycling on the high limit thermostat. But you will not be able to interpret that until after the heater has been replaced. There’s no sense in checking the contacts of the control thermostat because we know that they are closed. We know this because in order for the heater to fail, the control thermostat contacts must be intact to allow voltage to be applied to the heater.
If there is no obvious break in the heater resistance coil, it may still be defective. The next thing that you should do is isolate the heater by removing one of the terminals supplying voltage to the heater. If you are unsure of your ability, you can remove both terminals that supply voltage to the heater. Now you can use an ohmmeter to check the resistance of the heater. A good dryer heater will show a resistance in the range of 5 to 30 ohms. If you are using a digital meter, (by the way we recommend that you use a digital multimeter), touch the two leads together so that you can see what happens when your meter reads zero resistance.
Notice when you touch the two leads together, the meter display goes down to zero, indicating zero resistance. When you separate the two leads from the meter, observe the display to see what happens. Most of the time it will just blink, depending on the brand multimeter that you have. When you place your multimeter leads on the heater terminal, if the heater is open, in other words broken in some place that is not obvious, the meter will continue to blink. This means that the heater must be replaced.
Sometimes when you get to the dryer heating element to inspect it, Mac’s Appliance Repair of McKinney
find that one of the wires supplying voltage to the heater has burned in half. If you find a wire lead to a heater burned in half, you do not have to check the heater. In order for that wire to fail, the heater would have to be producing heat, and current would have to be passing through the wire. Of course you will have to repair the wire, but you should look for a vent restriction, or other condition that is causing the dryer to get too hot. This is actually a common problem with dryers that have the heater located behind the drum, such as Frigidaire and GE dryers. The problem happens when the customer opens the door to remove the clothing before the end of the cycle. When this happens the heater is on full blast, and has not had a chance to go through the cool down cycle. The heat from the heater radiates up to the wire terminals and sometimes causes them to deteriorate, or get brittle.