A typical dryer has many moving parts. But none are as crucial as the thermal fuse and the thermal cutoff, because they keep you safe. The thermal fuse is a safety mechanism that, when triggered, stops electrical flow to the heating element after it senses extreme heat. The thermal cutoff works similarly but for different reasons. It disconnects power to your dryer if it’s determined that something is wrong with your dryer.
Dryer Keeps Blowing Thermal Fuse – Troubleshoot and Diagnosis
If your dryer keeps blowing thermal fuse, you could be dealing with a few common issues. Before replacing the fuse, make sure that both the thermal fuse on the blower wheel and the cutoff fuse on the heater assembly is not blown. We’ll discuss some troubleshooting and possible solutions to fix your problem.
Check Thermal Fuse On Blower Wheel
The Dryer’s Thermal Cutoff is designed to trip on high heat to protect the dryer and your clothes. The thermal fuse can be checked by using a multimeter set on ohms (Ω). Measure the continuity of the thermal fuse between the two terminals. If no continuity exists, then replace the thermal fuse. Check all wires for looseness at ends and terminals.
If you want to repair or replace a fuse on your dryer, first turn the power off by turning the dryer’s power cord off from the wall outlet. Once you’re sure that the dryer is unplugged, flip up the top panel by removing its screws and set aside.
Control Board Relay Is Not Working
In many modern dryers, the thermal fuse is a safety device that cuts power to the heating element if it detects high heat. In some cases, however, a thermal fuse can be tripped by a bad relay. In this case, the relay may be stuck in “ON” position and fail to receive commands from the thermostat. The heating element will thus remain active despite the thermostat’s signal to cut off power.
This faulty part will cause your dryer to not heat and run indefinitely. This issue arises when the control board relay sends power to the heating element even when your dryer is not in use. It will send power if the dryer is running, but it won’t if it’s off.
When the dryer reaches its critical temperature, the thermal fuse inside the heating assembly will blow, shutting off the power to the dryer. This will require that you replace both the thermal fuse and the control board, since the relay is now stuck.
In the event that you need to replace a control board, here’s how to do it:
- Unplug dryer from outlet. Locate the screws on the back of the dryer that hold the control panel in place.
- Use a screwdriver to remove these screws and set them aside, as you will reinstall them later.
- Flip the control panel over and reveal the control board.
- The control board relay switch should be on the lower right of the board.
- Look for any signs of melting or blackening to indicate an issue with your control board. If black marks are present, it’s burnt out, you’ll need to replace it.
Remove all Lint Around Thermal Fuse
As lint is collected, it can easily bypass the lint trap and end up in areas such as the dryer vent. While this can be quite common, our products are designed to protect against such mishaps — particularly through use of thermal fuses and other safety measures. When lint does happen to make its way into places like the inner workings of a dryer drum, though, it can cause damage and lead to break down and failure over time.
Once lint is trapped inside your dryer’s ventilation system, it can cause overheating of the thermal fuse. This, in turn, will trigger the fuse to blow out.
If the dryer is not working, there are a few things you can do. First, look for a lint filter under the chute and remove all the lint from it. Next, you’ll need to check for a thermal fuse which will be located near the blower motor. If it’s burnt out, you’ll need to replace it.
Dryer Thermal Cutoff Fuse Keeps Tripping
The thermal cutoff is located at the base of the dryer and it works to cut off the flow of energy should that dryer overheats. It also serves to monitor the temperature of the dryer so you can ensure it’s heating up at an appropriate rate.
You may see a small amount of heat, but the dryer isn’t drying your clothes at a reasonable rate. To troubleshoot the issue, test for electrical continuity. You’ll also want to test for broken or shorted wires and for signs of wear and tear.
Clogged Dryer Vent
When your dryer’s heating unit overheats, it can cause a thermal cutoff fuse to trip. This happens when lint builds up in your dryer’s ventilation duct, preventing proper circulation of air. To get your dryer back in working order, check the back of the dryer to remove any clogs or lint buildup.
The clog may be as small as a piece of lint or as large as a sock, but whatever it is, it’s keeping the clothes from drying properly. In order to remove the clog, you’ll need to remove the vent from your dryer.
- Unplug the clothes dryer.
- Locate the dryer vent on the back of the machine. This is usually behind a panel; it could also be on top of your dryer, or on the side. On some machines, you will find both a lint screen and a vent. It could look like a mesh screen or like a tube that protrudes from the top of your machine.
- Remove the vent that leads from your dryer to the outdoors
- Position the dryer in such a place where you can work freely.
- To clean the air duct in the laundry room, clear away any obstructions in front of or behind your machine. Also, test that the vents are clear by blowing into them. If you notice a blockage, reach inside the vent and remove any toys or clothes that have fallen in.
- The easiest way to locate the exterior vent is by looking at the pipe leading into your home’s interior. The exterior vent should be located on the same side of the house as that pipe, either above or below it.
- Be sure to check the entire line from the machine to vents. You might have some blockage that can be cleared away with a small brush.
- Before you re-connect everything, make sure you’ve removed all of the lint from the dryer. (And don’t forget to check the exhaust pipe!) When you’re ready, reconnect all of your hoses and re-check that your dryer functions correctly.
Check If Heating Element is Grounded
If the coils in your dryer’s heating element touch the casing, it can cause the heating element to become grounded. Grounded coils can keep your dryer’s heat engaged even during air-only or fluff cycles, causing the machine to work harder than is necessary and damaging your clothing over time.
If the dryer’s heating element malfunctions, it’ll stop producing heat at all. The thermostat (the device that tells the unit when to turn on) will be unable to control how much heat is produced by the heating element, and your dryer will overheat. This will trip the thermal cutoff fuse, which stops power from reaching the heating element, preventing fire damage.
To Fix this issue do the following:
- Disconnect the Dryer from Power Supply.
- Remove the rear panel from the dryer and disconnect the two wires leading to the heating element.
- The heating element is down at the bottom, so you’ll need to disconnect the wires leading to it.
- Be sure to mark where each wire goes, so you can easily reconnect them after the repair.
- Replace the thermostat that’s on your old heating element with the new thermostat that comes with your new heating element.
- Assemble the heating element to the heater box and make sure the screw is secure.
- Reconnect all the wires.
- place the back panel.
- plug in the dryer and test if it works.
The thermal fuse and the cutoff switch might not feel like they’re very important — but they are. Without them, your dryer would overheat and be a serious fire hazard and will cause dryer keeps blowing thermal fuse issue. Don’t forget about the thermal fuse when you start having problems with your dryer — it’s there to help keep you safe. Also, remember to check the actual problem that causes it to trip when it does.