How to Test a Dryer Thermistor?

To test a dryer thermistor, use a multimeter to measure the resistance and compare it to the manufacturer’s specifications. The thermistor is a crucial component in a dryer’s heating system, and it helps regulate the temperature.

By testing the resistance, you can determine if the thermistor is functioning properly or if it needs to be replaced. This simple process ensures that your dryer operates efficiently and prevents potential overheating issues. Whether you are experiencing issues with your dryer or performing regular maintenance, testing the thermistor is a straightforward way to assess its functionality and ensure optimal performance.

What Is A Dryer Thermistor?

Brief Overview Of What A Dryer Thermistor Is

A dryer thermistor is a vital component of a clothes dryer that measures the temperature of the exhaust air. It is a temperature-sensing device that plays a key role in regulating and maintaining the operating temperature of the dryer.

The dryer thermistor acts as a sensor, sending signals to the control board to adjust the heating element or turn off the dryer if the temperature becomes too high. It helps ensure that your dryer operates efficiently and safely by preventing overheating and potential fire hazards.

Importance Of The Thermistor In Dryer Operation

The thermistor in your dryer is crucial for maintaining the optimal temperature during the drying process. Its primary purpose is to monitor the heat, ensuring it remains at the appropriate level to dry your clothes effectively without causing damage.

Without a properly functioning thermistor, several issues can occur. If the thermistor fails or malfunctions, your dryer may overheat, leading to potential fires or damage to the dryer itself. On the other hand, if the thermistor is faulty and signals the control board incorrectly, your dryer may not heat up enough, resulting in damp clothes even after a full drying cycle.

By regularly testing and maintaining the thermistor in your dryer, you can prevent these problems from occurring and prolong the lifespan of your appliance. It is important to know how to test a dryer thermistor to identify any issues and address them promptly.

Signs Of A Faulty Dryer Thermistor

A dryer thermistor is an essential component that helps regulate the temperature inside your dryer. It measures the temperature and signals the heating element to turn on or off accordingly. However, like any other electronic part, the thermistor can develop faults over time.

Identifying these faults is crucial to ensure your dryer functions optimally. In this section, we will discuss the common symptoms of a faulty dryer thermistor and how they can affect the dryer’s performance.

Common Symptoms Of A Faulty Dryer Thermistor

When it comes to a faulty dryer thermistor, there are several telltale signs that indicate something might be wrong. It is important to pay attention to these symptoms and take prompt action to avoid further damage. Here are the most common symptoms:

  1. Unusual temperature fluctuations: A faulty thermistor can cause your dryer to produce either too much heat or not enough heat. You may notice that your clothes are not drying properly or that they come out overly wrinkled. These temperature fluctuations are a clear indication that your thermistor is not functioning as it should.
  2. Inaccurate temperature readings: A working thermistor should provide accurate temperature measurements. However, a faulty one may display inaccurate readings, causing the dryer to operate at incorrect temperature settings. This can lead to inefficient drying cycles and can potentially damage your clothes.
  3. Extended drying time: If you find that your dryer takes longer than usual to dry a load of laundry, this could be another symptom of a faulty thermistor. The inconsistency in temperature regulation caused by the defective thermistor can result in extended drying times, wasting your time and energy.
  4. Inconsistent or no heat at all: One of the most obvious signs of a faulty thermistor is when your dryer stops producing heat altogether. This can be a frustrating experience, especially if you rely on your dryer for regular laundry. Lack of heat often points directly to a malfunctioning thermistor.
  5. Error codes: Certain dryer models are equipped with error codes that help diagnose issues. A faulty thermistor can trigger error codes, such as E1 or E2. If you see these codes flashing on your dryer’s display, it’s a strong indication that your thermistor needs attention.

How These Symptoms Affect Dryer Performance?

It’s important to understand how these symptoms affect your dryer’s overall performance in order to address the issue effectively. Here’s how each symptom impacts your dryer:

  1. Unusual temperature fluctuations can lead to inefficient drying, wasting time and energy.
  2. Inaccurate temperature readings can result in improperly dried clothes or even damage delicate fabrics.
  3. Extended drying time not only wastes energy but also indicates that your dryer is not operating efficiently.
  4. A lack of heat can render your dryer completely ineffective at drying clothes.
  5. Error codes provide valuable diagnostic information, alerting you to a problem and helping you take appropriate action.

Understanding these impacts will enable you to recognize the significance of a faulty dryer thermistor and take the necessary steps to address the issue promptly. In the next sections, we will explore how to test a dryer thermistor and how to replace it if necessary.

Tools And Equipment Needed

When it comes to testing a dryer thermistor, having the right tools and equipment is vital to ensure accurate results. Using the correct tools not only makes the process easier but also helps in obtaining precise measurements. In this section, we will explore the list of tools and equipment required for testing the dryer thermistor and highlight the importance of using them correctly.

List Of Tools And Equipment Required For Testing The Dryer Thermistor

Before embarking on the task of testing a dryer thermistor, it is crucial to gather all the necessary tools and equipment. By having them readily available, you can complete the task efficiently without any interruptions. The following is a comprehensive list of tools and equipment that you will need for this process:

  1. Multimeter:
    • A handheld digital multimeter with resistance-measuring capabilities is essential for this task. It allows you to measure the resistance values accurately.
  2. Thermistor chart or specifications:
    • A thermistor chart or specifications provided by the manufacturer are valuable resources. They help in interpreting the resistance values obtained during the test in relation to the expected range.
  3. Safety gloves and goggles:
    • Keeping safety in mind, it is important to wear gloves and goggles to protect yourself from any potential electrical hazards while working with the dryer.

Importance Of Using The Correct Tools For Accurate Results

Using the correct tools is paramount when testing a dryer thermistor to ensure accurate results. Here’s why it matters:

  • Accuracy: Precise measurements obtained with the help of a multimeter enable you to evaluate the condition of the thermistor accurately. This ensures that you identify any issues or malfunctions correctly.
  • Efficiency: With the appropriate tools and equipment, the testing process becomes more efficient. You can swiftly measure the resistance values, compare them with the specifications, and draw conclusions about the thermistor’s functionality.
  • Safety: Wearing safety gloves and goggles provides protection against potential electrical hazards. By prioritizing safety, you reduce the risk of accidents and ensure a smooth testing experience.

By using the correct tools for testing a dryer thermistor, you enhance the accuracy, efficiency, and safety of the process. The tools and equipment mentioned above will equip you with everything you need to conduct a thorough and reliable test.

Step-by-step Guide To Testing A Dryer Thermistor

Testing a dryer thermistor is a crucial step in diagnosing and fixing issues with your dryer. The thermistor is responsible for monitoring the temperature inside your dryer and sending signals to the control board. If your dryer is not heating properly or is overheating, the thermistor may be at fault. In this step-by-step guide, we will walk you through the process of testing a dryer thermistor to determine if it is functioning correctly.

Precautions To Take Before Starting The Testing Process

Before you begin testing the dryer thermistor, it is important to take certain precautions to ensure your safety:

  • Unplug the dryer from the power source to prevent electrical shock.
  • Wear protective gloves to avoid injuring yourself on sharp edges or hot components.
  • Allow the dryer to cool down completely before starting the testing process.

Step 1: Accessing The Dryer’s Control Panel

In order to access the control panel of your dryer, you will typically need to remove the top panel or front panel. Refer to your dryer’s user manual for specific instructions on how to remove these panels.

Step 2: Locating The Thermistor

Once you have accessed the control panel, you will need to locate the thermistor. The thermistor is a small sensor usually located near the dryer’s heating element or at the back of the dryer drum.

Step 3: Disconnecting The Thermistor From The Wiring Harness

To test the thermistor, you will need to disconnect it from the wiring harness. Carefully remove the wires connected to the thermistor by gently pulling on the connectors. Take note of the wire colors and their corresponding terminals to ensure proper reconnection later.

Step 4: Testing The Thermistor Using A Multimeter

Using a multimeter set to the resistance (ohms) function, you can test the thermistor for continuity. Touch the multimeter probes to the terminals of the thermistor and observe the reading on the multimeter display. A functional thermistor should display a resistance within the manufacturer’s specified range.

Step 5: Interpreting The Multimeter Readings

After testing the thermistor, you will need to interpret the multimeter readings. If the resistance reading is within the specified range, it indicates that the thermistor is functioning correctly. However, if the resistance reading is outside the specified range or shows no continuity, it indicates a faulty thermistor that needs to be replaced.

Step 6: Comparing The Readings To The Manufacturer’s Specifications

It is important to compare the resistance readings obtained from testing the thermistor to the manufacturer’s specifications. These specifications can usually be found in the dryer’s user manual or by contacting the manufacturer directly. If the readings deviate significantly from the specified range, it is likely that the thermistor is faulty and needs to be replaced.

Step 7: Reconnecting The Thermistor And Reassembling The Dryer

Once you have finished testing the thermistor and determined whether it is faulty or not, it is time to reconnect the thermistor to the wiring harness. Carefully attach each wire to its corresponding terminal and ensure they are securely connected. Afterward, reassemble the dryer by replacing the panels you removed in Step 1.

Troubleshooting Tips For Common Issues

When it comes to troubleshooting a dryer thermistor, understanding the common issues and how to identify them can save you time and money. The thermistor is a crucial component of your dryer’s temperature control system, detecting the temperature inside the appliance and relaying it to the control board.

If the thermistor is faulty or out-of-spec, it can lead to issues such as overheating, fabric damage, or ineffective drying. In this section, we will explore troubleshooting tips for different scenarios based on the test results, possible solutions for faulty or out-of-spec thermistors, and the importance of consulting a professional if unsure about the next steps.

Troubleshooting Tips For Different Scenarios Based On The Test Results

To troubleshoot your dryer thermistor effectively, you can perform a simple resistance test using a multimeter. This test will help you determine whether the thermistor is working properly or if it requires attention. Based on the test results, you can follow these troubleshooting tips:

  • If the resistance reading is within the specified range: In this scenario, the thermistor is functioning correctly, and the issue might lie elsewhere in the dryer system. You should check for other potential causes such as clogged vents, damaged heating elements, or faulty control boards.
  • If the resistance reading is too high: This indicates that the thermistor is experiencing resistance above the normal range. A high resistance reading can lead to inaccurate temperature readings by the control board, resulting in inadequate drying or prolonged drying cycles. In this case, you should consider checking the thermistor harness for loose connections and ensuring proper thermal coupling with the dryer’s airflow system.
  • If the resistance reading is too low: A low resistance reading suggests that the thermistor is experiencing less resistance than expected. This can cause the dryer to overheat, potentially leading to scorched fabrics, damaged components, or even fire hazards. If you encounter a low resistance reading, it is essential to inspect the thermistor wiring for any short circuits or exposed wires.

Possible Solutions For Faulty Or Out-of-spec Thermistors

If you find that your dryer thermistor is faulty or out-of-spec, there are several possible solutions to resolve the issue. These solutions include:

  1. Replacing the thermistor: If the thermistor is defective and no longer functioning correctly, replacing it with a new one can restore proper temperature control and prevent further complications.
  2. Inspecting the wiring harness: In some cases, the issue may lie with the wiring harness rather than the thermistor itself. Ensure that the wiring connections are secure and free from any damage or corrosion.
  3. Checking the dryer’s ventilation system: A clogged or restricted dryer vent can disrupt proper airflow, causing temperature fluctuations and potential thermistor issues. Regularly clean and inspect the vent system to ensure optimal performance.
  4. Testing related components: While troubleshooting the thermistor, it is wise to test other related components such as the control board, heating elements, and thermal fuses. These components work in conjunction with the thermistor and can impact its performance if faulty.

Importance Of Consulting A Professional If Unsure About The Next Steps

If you are uncertain about the next steps to take after testing your dryer thermistor, it is crucial to consult a professional technician. Attempting complex repairs or making incorrect adjustments can worsen the issue or pose safety risks.

A professional can accurately diagnose the problem, provide expert guidance, and ensure that the repair process is carried out effectively. Remember, the safety of yourself, your appliance, and your home should always be a priority when dealing with dryer issues.

Frequently Asked Questions On How To Test A Dryer Thermistor

How Do You Know If A Dryer Thermistor Is Bad?

A bad dryer thermistor can result in temperature issues. Signs of a faulty thermistor include inconsistent heat, excessive drying time, or no heat at all.

How Do You Check If A Thermistor Is Working?

To check if a thermistor is working, use a multimeter to measure its resistance. Disconnect it from any power source and ensure it is at room temperature. Connect the multimeter leads to the thermistor terminals and check the resistance reading.

A working thermistor will show a resistance within its specified range.

Should A Thermistor Have Continuity?

Yes, a thermistor should have continuity. It should allow the flow of electric current without interruptions for it to function correctly.

Will A Bad Thermistor Cause Dryer Not To Run?

A bad thermistor can cause a dryer to not run properly.

How Do You Know If A Dryer Thermistor Is Bad?

If your dryer is running too hot or not heating at all, it could be a sign of a faulty thermistor.


To conclude, testing a dryer thermistor is an essential step in troubleshooting dryer issues. By following the simple steps outlined in this guide, you can easily determine if the thermistor is functioning correctly or needs to be replaced. Remember to always prioritize safety and consult a professional if needed.

With this knowledge, you can save time and money by fixing the problem yourself. So, go ahead and confidently tackle any dryer thermistor issues that may arise.

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