Various options on how to test a thermal fuse
Has your appliance stopped producing heat? A broken heating element should come to the forefront of the list of usual suspects. But before going through the trouble and expense of replacing the heating element, you should test the device’s thermal fuse.
This is a safety device that blocks the flow of electricity to the heating mechanisms when the product exceeds a predetermined maximum temperature.
Testing the thermal fuse in your appliance is simple and can usually be done using various methods, all in less than 5 minutes.
Here, we teach you how to test a thermal fuse without a multimeter and how to test a fuse with an ohmmeter or multimeter.
How to test the fuse with a voltage tester
If you do not have a multimeter at hand or do not have one, you can test the thermal fuse with a test lamp, also known as a test light, mains tester, and voltage tester. Keep your money in your pocket, here is a tutorial on how to make a homemade fuse test.
- A test lamp
Unlike the test with a digital multimeter, in this test, it is required that the ignition switch is in the “ON” position since some fuses are only powered with the switch in this position. Such is the case of the lights of the headlights in some cars. This usually is in the secondary fuse boxes.
- The first step is to connect the gator from the test lamp to the negative battery.
- After that, we will try to turn on the test lamp; this is done by tapping the positive side of the battery and then we will test the fuses.
- As with the multimeter, you will have to touch the two terminals of the fuse. If this is in good condition, the light of the test lamp should turn on.
- In case the test lamp does not light with a specific fuse, we can remove it to check it. In the internal part, they have a metallic connection (or filament for the small fuses) which when the fuse is burned, it is normally open.
How to test a thermal fuse with an ohmmeter
An ohmmeter is an electronic instrument that will help you determine if the thermal fuse is allowing the electricity to reach the device’s heating mechanisms. It can also be used to test a thermal fuse.
- An ohmmeter
- A screwdriver
- Unplug the appliance from the power outlet before troubleshooting. Make sure all electricity is disconnected from the appliance before proceeding.
- Find out where the thermal fuse is in your home appliance. The placement may vary depending on the brand and the device. Sometimes, the thermal fuse is behind the rear panel of the device, and sometimes it can be found behind the lower base panel.
- Remove the appropriate apparatus plate to reveal the thermal fuse.
- Access a thermal fuse in the back of the appliance by loosening the screws that fix the rear panel.
- Set the screws and the back panel aside until you are ready to replace them.
- Access a thermal fuse on the front of the device by using a screwdriver to apply pressure to the two metal clips that hold the foot panel in place. The clips are about 4 inches from the sides of the panel. When the panel comes free, leave it aside until you have completed your repair.
- Look for a white plastic strip with two cables connected to it. This is the thermal fuse. Disconnect both cables from the thermal fuse.
- Set an ohmmeter to the Rx1 configuration.
- Touch the ohmmeter probes to the ends of the thermal fuse.
- Read the display on the ohmmeter to determine if the thermal fuse is faulty. If the ohmmeter needle moves to “0”, the fuse is functional and does not need to be replaced.
- Replace the blown thermal fuse if the needle does not move the ohmmeter.
If you end up having to replace the thermal fuse in the home appliance, replacements can be purchased from your local computer parts store or online stores for less than $3 or thereabouts.
How to test a fuse with a multimeter
In this part, we will see how to test the fuse of a car with a digital multimeter.
- This test is going to be done with the car off and with the ignition switch in the “OFF” option.
- If you have any device that is consuming current, you have to deactivate them or turn them off.
- This with the aim of not damaging the multimeter and obtaining a more reliable diagnosis of the test.
- Put the multimeter’s knob in the continuity option since we are going to be testing continuity between the dude’s terminals. With this, we will find out if the fuse is burned, open or damaged.
- Once we have the multimeter ready, we will touch with the tips on the top of the fuse. They have a hole at each end which is used to make this test. This hole is in contact with the terminals of the fuse. If when touching the two terminals of the fuse the multimeter emits a “beep” this indicates that the fuse is in good condition since there is continuity in it.
The video below will help you:
How to repair the thermal fuse in a dryer
As earlier mentioned, the thermal fuse in the dryer at home is a safety mechanism. The fuse is designed to explode when the internal temperature of the dryer is too high, creating a fire hazard.
When the fuse blows, the dryer stops working. The fuse is usually located on the back of the dryer, near the exhaust outlet.
Since changing the fuse only requires removing the back cover of the dryer. It is a task anyone can achieve. All dryers are slightly different, so you should refer to the documentation that accompanies the dryer before continuing.
- Philips screwdriver
- New thermal fuse
- Unplug the dryer from the electrical outlet.
- Disconnect the dryer from the exhaust port on the back of the dryer.
- Slide the dryer off the wall, preferably about 4 feet, so you have plenty of workspace behind the dryer.
- Remove the panel from the back cover of the dryer. Typically, several screws along the sides of the back panel must be removed to remove the back panel.
- Once the screws are removed with a Phillips screwdriver, lift the back panel up and out of the bottom clips and keep it in reserve. Be careful as the edges of the back panel are sharp.
- Remove the blown thermal fuse. In most dryers, the thermal fuse is mounted on the side of the exhaust duct.
- Look for a white piece of plastic with a cable attached to each side. Remove the screws that hold it in place. Disconnect the wires from each end of the wick and detach from it. Like many fuses, a thermal fuse cannot be repaired, it is only replaced.
- Connect the cables to the new thermal fuse and reassemble the fuse into the exhaust conduit.
- Place the back cover of your dryer and reconnect the vent. Plug the dryer in and test the new fuse.
- If the thermal fuse blows again, there may be a more serious problem with the dryer. Contact an appliance repair service to help determine the problem.
- Never work in the dryer while it’s plugged into the power outlet.
We hope you have found a way to test thermal fuses with and without a multimeter. Kindly let us know in the comment section if any of these tutorials work for you or if you know of more effective remedies. Don’t forget to share this article “How To Test A Thermal Fuse Without A Multimeter“.
Read more: How can you check a thermostat?