Why Your Dryer’s Thermal Fuse Keeps Blowing and How to Bypass It?

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Ever wondered why your dryer’s thermal fuse keeps blowing at the worst possible times? In this guide, we’ll unravel the mystery behind this pesky problem and discuss whether bypassing it is a viable solution. Get ready to troubleshoot and regain control of your laundry routine!

Why Does Your Dryer’s Thermal Fuse Keep Blowing?

So, let’s roll up our sleeves and understand why your dryer’s thermal fuse keeps blowing and how to prevent it from happening again.

Thermal (Limit) Fuse on the Blower Wheel

The thermal fuse located on your dryer’s blower wheel is a crucial safety component. Its primary function is to monitor the temperature inside the dryer. When the temperature reaches an unsafe level, the thermal fuse shuts off power to the motor, preventing a potential fire hazard. If you suspect this fuse is the culprit, here’s how to diagnose and fix it:

Diagnosis:

  • Ensure the dryer’s 240V power cord is switched OFF from the wall.
  • Use a multimeter to check for continuity between the two contacts on the thermal fuse.

Fix:

  • If the thermal fuse is blown, it must be replaced. Remember that thermal fuses are one-time use parts and cannot be reset.

 

Failed Relay on the Control Board

In some cases, especially with Whirlpool and Maytag dryers, the thermal fuse keeps tripping due to a malfunctioning relay on the control board. This relay may become stuck in the “ON” position, causing power to flow continuously to the heating element regardless of the ON/OFF commands from the control board.

Diagnosis:

  • If your dryer continues to produce heat even when it should be off, a failed relay on the control board could be the issue.

Fix:

  • Replace the control board or the specific relay that’s causing the problem. This may require some technical expertise or the help of a professional technician.

 

Lint Wrapped Around the Thermal Fuse

Lint is the nemesis of dryers. It has a sneaky way of bypassing the lint trap and accumulating in the wrong places, including around the thermal fuse inside the blower wheel. When lint accumulates in this area, it can cause the fuse to overheat and blow due to heat build-up.

Diagnosis:

  • If you suspect lint accumulation is the issue, you’ll need to access the blower wheel and inspect it for lint and debris.

Fix:

  • Clean all lint and debris from around the blower wheel, especially the area near the thermal fuse.
  • Replace the thermal fuse if it’s damaged or malfunctioning.

 

Thermal Cutoff (Heater Assembly) Fuse Keeps Tripping

The thermal cutoff, located on the heater assembly, plays a critical role in regulating the dryer’s temperature. It ensures that the dryer doesn’t get too hot, preventing overheating-related issues. When this fuse repeatedly trips, it’s an indication of an underlying problem.

Diagnosis:

  • If your dryer drum is spinning but not producing heat or generating insufficient heat, the thermal cutoff may be at fault.

Fix:

  • Test the thermal cutoff for electrical continuity using a multimeter.
  • Identify and rectify the root cause of the thermal cutoff failure, which could be any of the following issues:
  1. Dryer Hose or Vent Line Clogged: This is the most common reason for thermal cutoff fuse tripping. To fix it:
  • Unplug the dryer.
  • Remove the vent line from the back of the dryer and clean it thoroughly.
  • Clean the interior side of the vent duct and the exterior vent on the outside of your home.
  • Ensure there are no obstructions like bird nests.
  1. Heating Element Grounded: When the heating element’s coils touch the metal casing, it can become grounded, causing the heating element to remain constantly “ON.” To fix the same
  • Unplug the machine.
  • Remove the back panel from the dryer.
  • Disconnect the wires from the old heating element, marking their locations.
  • Transfer the high-heat thermostat from the old heating element to the new one.
  • Properly position and secure the new heating element to the heater box.
  • Reconnect the wires and back panel.
  • Plug in the dryer and test it to ensure it’s working properly.

 

How to Bypass A Dryer’s Thermal Fuse?

Troubleshooting your dryer by bypassing a thermal fuse requires safety and responsibility. Bypassing should only be used for diagnostics, and you should never run your dryer without a thermal fuse.
Having said that here are the steps to safely bypass a dryer’s thermal fuse:

Step #1: Unplug Your Dryer

Safety first! Always turn off your dryer first. This step disables the unit’s power, reducing bypass risk. Your dryer’s manual will help you find the thermal fuse. Online guides for different dryer brands and models can help if you don’t have the manual.

The thermal fuse is usually hidden under the bottom front panel or behind the rear panel.

  • For bottom front panel access: Use a flathead screwdriver to detach the kick panel or loosen metal hooks securing it. Once removed, you’ll have access to the thermal fuse.
  • For rear panel access: Unscrew the four corner screws holding the back panel in place to remove it.

Step #2: Locate and Turn Off the Thermal Fuse

Now that you have the thermal fuse, identify it. The thermal fuse is usually a small white plastic strip with wires on each end. Electrical tape the wire ends together to temporarily bypass the thermal fuse. This “jumps” the fuse, letting you continue diagnostics.

Run the dryer for no more than 90 seconds on a heat cycle with the fuse bypassed. Long-term use without a thermal fuse can damage the dryer and endanger users.

Step #3: Replace the Blown Thermal Fuse (If Necessary)

After bypassing the thermal fuse, your dryer should heat up, indicating the fuse caused the problem. To restore protection, replace the thermal fuse immediately. A working thermal fuse prevents overheating and fires.

If bypassing the thermal fuse doesn’t work, a faulty heating element may be to blame. Systematically eliminating all options is crucial.

Step #4: Remove the Fuse Bypass

After diagnosing the problem and finding the root cause, remove the electrical tape bypassing the thermal fuse. This restores your dryer’s safety features.

Bypassing the thermal fuse should be a last resort if you have a multimeter, ohmmeter, or can test at a repair shop. Safety first, use the bypass to troubleshoot temporarily.

Remember that bypassing a thermal fuse is not a long-term solution and that a working dryer should be used.

A functional thermal fuse protects your appliance and prevents fires.

 

How to Test a Thermal Fuse?

Testing a thermal fuse is a straightforward process, but it’s important to note that you should attempt this only if you have some experience with appliance repair and are comfortable using a multimeter. If you meet these criteria, follow these steps to test a thermal fuse:

Step 1: Ensure Safety Precautions

Safety comes first when testing the thermal fuse. Turn off the dryer power. Turn off the gas supply if your dryer is gas to avoid hazards.

Step 2: Locate the Thermal Fuse

The dryer’s exhaust duct holds the thermal fuse, which is one to two inches long. Your user manual will tell you where it is. Be prepared to disassemble the dryer’s side and top panels to reach the thermal fuse.

Step 3: Disconnect the Thermal Fuse

Carefully disconnect the thermal fuse from its wires after finding it. Carefully handle the wires because you’ll need to reconnect them.

Step 4: Test for Continuity

This requires a multimeter. Set your multimeter to continuity or ohms (Ω). This setting determines if the thermal fuse has an unbroken electrical current path.

Step 5: Test the Thermal Fuse

Touch one multimeter probe to each thermal fuse terminal. Since continuity testing only checks for an unbroken circuit, which probe goes where doesn’t matter. If the multimeter beeps or reads near zero ohms, the thermal fuse is continuous. The thermal fuse is working, so you can check other dryer parts.

Step 6: Interpret the Results

Your thermal fuse is blown if the multimeter shows no continuity (no beep or very high resistance). This discontinuity interrupts the thermal fuse’s electrical path, preventing overheating. This requires replacing the thermal fuse.

Step 7: Reconnect and Reassemble

If the thermal fuse is the problem, replace it. Make sure the wires are securely connected to the new thermal fuse. Reassemble any panels or covers you removed to reach the thermal fuse.

Step 8: Restore Power

After replacing the thermal fuse and reassembling it, power the dryer. Turn off the gas supply for gas dryers and turn it back on.

Step 9: Test the Dryer

To test your dryer after replacing and reconnecting it, run a test cycle. Check that the dryer heats up and runs smoothly.

 

How To Perform A Dryer Thermal Fuse Replacement?

Below we’ll walk you through the process of performing a dryer thermal fuse replacement, ensuring your appliance gets back in working order.

Step 1: Secure the Replacement Part

Before diving into the replacement process, make sure you have the correct replacement thermal fuse on hand. Fortunately, major dryer manufacturers like Maytag, Samsung, Whirlpool, and LG offer these replacement parts at affordable prices.

Step 2: Safety First – Power Off

Begin by ensuring the safety of your work environment. Turn off the power supply to your dryer. This step is absolutely crucial to prevent any electrical accidents during the replacement process. Safety should always come first.

Step 3: Gain Access to the Thermal Fuse

In most dryers, you’ll need to access the thermal fuse by removing the top and/or side panels. The exact procedure for panel removal may vary depending on your dryer’s make and model. Refer to your dryer’s user manual for specific instructions on panel removal. This step is essential to reach the thermal fuse housing.

Step 4: Remove the Blown Thermal Fuse

Once you have access to the thermal fuse housing, locate the thermal fuse. It is typically a small, rectangular component secured in place by mounting screws. Carefully unthread these screws to release the thermal fuse. Next, disconnect the wires attached to the thermal fuse. Take note of their positions or consider labeling them to ensure a proper reconnection later.

Step 5: Connect the New Thermal Fuse

Now, it’s time to install the replacement thermal fuse. Start by attaching the wires to the new thermal fuse, ensuring that they are securely connected. Double-check to match the wires correctly based on your earlier labeling or notes.

Step 6: Secure the New Thermal Fuse

With the wires connected, position the new thermal fuse in the same location where you removed the old one. Carefully thread the mounting screws back into place to secure the thermal fuse firmly. Make sure it is snugly attached to prevent any loose connections.

Step 7: Reassemble the Dryer

After successfully replacing the thermal fuse, it’s time to put your dryer back together. Reattach the top and/or side panels that you removed in Step 3. Follow the reverse procedure of panel removal, ensuring each panel is securely in place.

Step 8: Restore Power

With the dryer reassembled, you’re almost there. Reconnect the power supply to your dryer. It’s crucial to ensure that the power supply is correctly connected, as improper connections can lead to safety hazards. Next, test the dryer to see if it is working properly.

 

How To Prevent The Thermal Fuse From Blowing Again?

Keeping your dryer running smoothly after replacing the thermal fuse is crucial. Consider these thermal fuse blowout prevention measures:

Regularly Clean the Dryer Lint Filter and Vent

Dryer lint causes thermal fuse blowouts. The lint is flammable and can build up in the dryer vent and lint filter. Buildup restricts airflow, causing the dryer to overheat and possibly trip the thermal fuse. Prevent this:

  • Maintenance: Clean the lint filter after each drying cycle. A clean filter improves airflow, preventing overheating.
  • Deep Cleaning: Clean your dryer vent system regularly. Remove the dryer vent and vacuum the lint. Check the exterior vent opening for bird nests or debris that can block airflow.

Ventilate Your Laundry Room

Maintaining a consistent dryer temperature requires proper laundry room ventilation. Airflow dissipates heat and reduces dryer workload.

Restoring your dryer’s performance after replacing the thermal fuse is crucial. Here’s how to ensure proper ventilation:

  • Leave enough space around your dryer for airflow. Avoid tight or enclosed dryer placement.
  • Check your dryer’s ventilation ducts. Make sure they’re not crushed, kinked, or blocked. Replace damaged or restrictive ducts to improve airflow.
  • Room ventilation is crucial, especially if your laundry area is small. For airflow and heat prevention, use a fan or window.

Check for Heating Element or Thermostat Issues

Overheating causes the thermal fuse to blow, so it’s important to find and fix the cause.

Check the heating element for damage or wear. As mentioned, coils touching the metal casing can keep the heating element on, causing overheating and thermal fuse blowouts. If you notice heating element issues, replace it immediately.

The dryer’s thermostat controls temperature. A broken thermostat can cause the dryer to overheat.

Check thermostat accuracy and consistency. Replace it if it’s broken to keep the dryer at safe temperatures.

 

Read More

  1. How Many Amps Does a Dryer Use? Everything You Need to Know
  2. CL Code on Lg Washer (Meaning and How to Fix It)

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