Honeywell Thermostat Fan Runs Constantly: Easy Fixing Guide

If your Honeywell thermostat fan runs constantly, check for a stuck fan relay or faulty wiring. This issue can lead to increased energy consumption and decreased comfort levels in your home.

It is essential to address this problem promptly to avoid potential damage to your HVAC system. In this blog post, we will explore common reasons why your thermostat fan may be running continuously and provide troubleshooting tips to resolve the issue effectively.

By following these guidelines, you can ensure optimal performance of your thermostat and maintain a comfortable indoor environment while saving on energy costs.

Introduction To Honeywell Thermostat Fan Issues

If your Honeywell thermostat fan runs constantly, it could be due to a wiring issue, a faulty fan limit switch, or a malfunctioning thermostat. To troubleshoot, check the wiring connections, inspect the fan limit switch, and ensure the thermostat settings are correct.

Regular maintenance can help prevent these issues.

If you own a Honeywell thermostat, you may have encountered the issue of your thermostat fan running constantly. This can be frustrating and may result in increased energy bills. There can be several reasons why your Honeywell thermostat fan runs constantly, and it’s essential to understand the common symptoms and impacts of this issue.

Common Symptoms Of A Continuously Running Fan

There are a few signs that indicate your Honeywell thermostat fan is running continuously. These include:

  • The fan runs even when the heating or cooling system is not in use.
  • The fan runs at a low or high speed consistently.
  • The fan runs for an extended period without turning off.

If you notice any of these symptoms, there may be an underlying issue with your thermostat fan.

Impact On Comfort And Energy Consumption

A continuously running Honeywell thermostat fan can impact both your comfort and energy consumption. When the fan runs constantly, it can create a draft and make your home feel colder than it should. Additionally, it can increase energy consumption, resulting in higher electricity bills.

To ensure your comfort and reduce energy consumption, it’s essential to address the issue of a continuously running fan promptly. This can be done by troubleshooting the problem or seeking professional help.

In conclusion, a continuously running Honeywell thermostat fan can be a frustrating issue that impacts both your comfort and energy bills. By understanding the common symptoms and impacts of this issue, you can take the necessary steps to resolve it promptly.

Initial Troubleshooting Steps

When your Honeywell thermostat fan runs constantly, it can be frustrating and lead to increased energy consumption. However, before calling for professional help, you can try some initial troubleshooting steps to potentially resolve the issue. By checking the thermostat settings and ensuring proper installation, you may be able to identify and fix the problem without any additional assistance.

Checking Thermostat Settings

Start by examining the thermostat settings to ensure they are correctly configured. Here’s what you can do:

  1. Check the fan setting: Make sure the fan is set to “Auto” rather than “On.” When set to “Auto,” the fan will only run when heating or cooling is actively taking place.
  2. Adjust the temperature: Verify that the desired temperature is set correctly. If the thermostat is set too high or low, it can cause the fan to run continuously.
  3. Check the programming: If your thermostat has programmable features, review the schedule to ensure there are no conflicts or errors.

Ensuring Proper Installation

Improper installation can also contribute to the constant running of your Honeywell thermostat fan. Take the following steps to ensure proper installation:

  1. Inspect the wiring: Ensure that all the wires connected to the thermostat are secure and properly connected. Loose or damaged wiring can cause malfunctions.
  2. Verify power source: Make sure the thermostat is receiving power. Check the circuit breaker to ensure it hasn’t tripped.
  3. Confirm compatibility: Ensure that your thermostat is compatible with your heating and cooling system. Refer to the thermostat’s manual or Honeywell’s website for compatibility information.

By following these initial troubleshooting steps, you can potentially identify and resolve the issue of your Honeywell thermostat fan running constantly. If the problem persists, it may be necessary to seek professional assistance to diagnose and address any underlying issues.

Understanding Fan Control Settings

Gain insights into Honeywell thermostat fan control settings to address a constantly running fan. Adjust settings for optimal comfort and energy efficiency. Understanding these settings can help maintain a balanced indoor climate while preventing unnecessary energy consumption.

Difference Between ‘auto’ And ‘on’ Modes

The Honeywell thermostat fan runs constantly when the fan setting is set to ‘On’ mode. In this mode, the fan will continue to run, regardless of whether the heating or cooling system is on or off. On the other hand, when the fan setting is set to ‘Auto’ mode, the fan will only run when the heating or cooling system is on.

This means that the fan will turn off automatically when the desired temperature is reached. To avoid running the fan constantly and save energy, it is recommended to set the fan control setting to ‘Auto’ mode.

Adjusting Fan Settings For Optimal Performance

It is important to adjust the fan settings on your Honeywell thermostat for optimal performance. To do this, follow these steps:

  1. Press the ‘Menu’ button on your thermostat.
  2. Use the arrow buttons to navigate to the ‘Fan’ option and press ‘Select’.
  3. Select ‘Auto’ mode to ensure the fan runs only when the heating or cooling system is on.
  4. Choose the fan ‘Circulate’ option to run the fan for a set amount of time per hour to improve air circulation in your home.
  5. Adjust the ‘Fan Schedule’ to set specific times for the fan to turn on and off.

By adjusting the fan settings on your Honeywell thermostat, you can improve the performance of your heating and cooling system, save energy, and maintain a comfortable temperature in your home.

Assessing The Thermostat Wiring

Assessing the thermostat wiring is crucial when dealing with a Honeywell thermostat fan that runs constantly. Check for loose or damaged wires and ensure that the wiring is properly connected to the thermostat.

Assessing the Thermostat Wiring

Signs Of Faulty Wiring

Look for loose or exposed wires that may cause malfunction.

  • Erratic cooling or heating behavior
  • Inconsistent fan operation
  • System not responding to thermostat settings

Safety Precautions During Inspection

Shut off power before checking wiring to prevent electrical accidents.

  1. Use a non-contact voltage tester to ensure power is off
  2. Wear insulated gloves and goggles for protection
  3. Avoid touching live wires to prevent shocks

Cleaning And Maintenance Tips

When it comes to your Honeywell thermostat, regular cleaning and maintenance are essential to ensure its efficient operation. By following some simple cleaning and maintenance tips, you can prevent issues such as the fan running constantly and extend the lifespan of your thermostat.

Routine Cleaning Of The Thermostat

Regular cleaning of your Honeywell thermostat is crucial for keeping it in optimal condition. Here are some simple steps you can follow to ensure your thermostat stays clean and functions properly:

  • Power off the thermostat: Before cleaning, make sure to switch off the power to the thermostat to avoid any mishaps.
  • Use a soft, dry cloth: Gently wipe the exterior of the thermostat with a soft, dry cloth to remove any dust or dirt buildup.
  • Clean the vents: Use a small brush or compressed air to clean the vents and remove any debris that may be obstructing airflow.
  • Inspect the wiring: Check the thermostat’s wiring for any signs of wear or damage and address any issues promptly.

When To Schedule Professional Maintenance

While routine cleaning can help maintain your Honeywell thermostat, there are instances when professional maintenance is necessary. Consider scheduling professional maintenance in the following situations:

  1. Faulty wiring: If you notice any issues with the thermostat’s wiring, it’s best to have a professional inspect and repair it to prevent any further damage.
  2. Inaccurate temperature readings: If your thermostat is displaying inaccurate temperature readings, it may require calibration or replacement of faulty components.
  3. Frequent cycling: If the thermostat is cycling on and off frequently, it could indicate a more complex issue that requires professional attention.

Troubleshooting The Hvac System

Troubleshooting the HVAC system is essential for maintaining a comfortable indoor environment and optimizing energy efficiency. When dealing with a Honeywell thermostat that causes the fan to run constantly, it’s important to investigate various aspects of the HVAC system to identify and address potential issues.

Investigating Issues Beyond The Thermostat

When the Honeywell thermostat is causing the fan to run constantly, it’s crucial to inspect components beyond the thermostat itself. Check the HVAC system’s wiring, connections, and control board for any potential malfunctions or loose connections. Additionally, assess the condition of the compressor and ensure that it is operating as intended.

When To Inspect Air Filters And Ductwork

Regular inspection of air filters and ductwork is vital to ensure proper airflow and prevent the fan from running constantly. Inspect air filters at least once a month and replace them if they are dirty or clogged. Similarly, examine the ductwork for any blockages, leaks, or obstructions that may impede airflow and cause the HVAC system to work harder than necessary.

Advanced Solutions

When dealing with a Honeywell thermostat fan that runs constantly, advanced solutions may be necessary to address the issue effectively. Here are some advanced troubleshooting methods that can help resolve this persistent problem.

Resetting The Thermostat

One of the initial steps to take when the Honeywell thermostat fan runs constantly is to perform a reset. This can be achieved by following a simple procedure:

  1. Locate the reset button on the thermostat.
  2. Press and hold the button for 10 seconds.
  3. Release the button and wait for the thermostat to restart.

Firmware Updates And Technical Fixes

Updating the firmware of the thermostat and implementing technical fixes can often resolve the issue of the fan running constantly. This involves:

  • Checking for firmware updates on the Honeywell website.
  • Downloading and installing the latest firmware version as per the manufacturer’s instructions.
  • Performing technical fixes such as replacing faulty components or calibrating the thermostat to ensure proper functioning.

When To Call A Professional

When your Honeywell thermostat fan runs constantly, it’s essential to know when to seek professional help. Some issues with your thermostat may require the expertise of a qualified HVAC technician. Identifying these problems and finding the right professional to address them is crucial for maintaining a comfortable and energy-efficient home environment.

Identifying Problems That Require Expert Attention

Several issues related to a Honeywell thermostat can indicate the need for professional intervention. If you experience any of the following problems, it’s advisable to seek the assistance of a skilled HVAC technician:

  • Malfunctioning wiring or electrical components
  • Inaccurate temperature readings
  • Frequent system cycling
  • Inability to control the fan or heating/cooling system
  • Unusual noises or odors

Finding A Qualified Hvac Technician

When searching for an HVAC technician to address your Honeywell thermostat issues, it’s important to ensure that you find a qualified and reputable professional. Consider the following factors when selecting an HVAC technician:

  1. Check for proper licensing and certifications
  2. Read customer reviews and testimonials
  3. Verify experience with Honeywell thermostat systems
  4. Request a written estimate for the service
  5. Ensure the technician offers a warranty for their work

Preventive Measures For Future Issues

Preventive measures are essential for ensuring that future issues with your Honeywell thermostat are minimized. By taking proactive steps, you can prevent the fan from running constantly and maintain the optimal functionality of your thermostat. Here are some preventive measures that you can implement to address potential issues:

Regular Maintenance Schedule

Implementing a regular maintenance schedule for your Honeywell thermostat is crucial for preventing future issues. Schedule periodic inspections and maintenance checks to ensure that the thermostat is functioning properly.

Cleaning the thermostat and ensuring that all components are free from dust and debris can help prevent issues such as the fan running constantly. Regularly replacing the air filters and checking for any signs of wear and tear can also contribute to the efficient operation of the thermostat.

Upgrading To A Smart Thermostat

Consider upgrading to a smart thermostat to enhance the functionality and efficiency of your HVAC system. Smart thermostats offer advanced features such as adaptive learning and remote access, allowing you to optimize the settings and prevent issues such as the fan running constantly.

Utilize the scheduling capabilities of smart thermostats to establish energy-saving settings and ensure that the fan operates as needed, reducing the likelihood of continuous operation.

Frequently Asked Questions

Why Does The Fan Run Constantly On My Honeywell Thermostat?

The fan on your Honeywell thermostat may run constantly due to a few reasons. It could be set to “ON” instead of “AUTO” mode, there may be a wiring issue, or the thermostat might need recalibration. Check the settings, inspect the wiring, and consider recalibrating the thermostat if necessary.

Why Won’t The Fan On My Thermostat Turn Off?

The fan on your thermostat may not turn off due to a faulty thermostat, wiring issues, or a malfunctioning fan relay. It’s best to turn off the power to the thermostat and call a professional to diagnose and fix the issue.

Why Is My Fan Running When My Thermostat Is Off?

Your fan may run when the thermostat is off due to a setting that keeps the fan running. Check your thermostat settings for fan operation options.

How Do I Shut Off The Fan On My Honeywell Thermostat?

To shut off the fan on your Honeywell thermostat, locate the fan setting on the device’s control panel. Change the setting to “Off” or “Auto” to stop the fan from running continuously.


A Honeywell thermostat fan running constantly can be a frustrating issue to deal with. However, by following the troubleshooting steps mentioned in this blog post, you can identify and resolve the underlying causes. Remember to check the thermostat settings, inspect the wiring, clean the fan blades, and consider contacting a professional if needed.

By addressing the problem promptly, you can ensure optimal performance and energy efficiency of your HVAC system.

Scott Maupin