How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the leading thermostat producers, and we proudly install them on a frequent basis in the U.S.. They’re durable and reliable. In addition, Honeywell is regularly updating its technology, bringing more features for your home.

Still, every thermostat can experience errors now and again. As a result, we’ve compiled this informative manual to go over troubleshooting. While Honeywell thermostat troubleshooting problems are rare, they do pop up.

While you can typically repair many thermostat problems by yourself, they often require Expert help. Our HVAC Experts are available to help when you need us. We’re only a call away at 866-397-3787.

Let’s get started with the process by finding out what type of thermostat your home has.

What Kind of Thermostat Do I Have?

There are three models of thermostats:

    • Manual—This is the classic dial-shaped thermostat. You won’t experience error codes with this one, but it’s also the least efficient for saving on energy costs.
    • Programmable—This thermostat features a digital screen and arrows you touch to choose your desired temperature. You can also use daily programs to lower the temperature when you’re gone and increase it when you come home.
    • Smart—You won’t have to make any programs on this thermostat, since it adjusts to your day. It instinctively raises and lowers the temperature when you or other household members are gone to help you save on heating and cooling bills. You can also raise or lower the temperature anywhere on your phone or other Wi-Fi-enabled device.

As is the case with most technologically advanced products, there are regular problems that might occur. Many of these troubles don’t call for professional help and are simple to fix on your own.

Common Honeywell Thermostat Troubleshooting Problems

Every Honeywell thermostat has a special set of codes assigned to the malfunctions that happen.

Think how easy it can be to repair a computer by restarting it. Many times, correcting a thermostat can be just as uncomplicated.

Here is a listing the most reported Honeywell thermostat problems. These apply to the following programmable thermostats:

Display is Blank

If the screen is blank on your programmable thermostat, you might need to replace the batteries. If that doesn’t solve the malfunction or you use a smart thermostat, there might be a wiring malfunction.

Next, you should make sure the power is on for your furnace or air handler. Verify the switch by the indoor equipment is switched “on”.

In addition to that, you should make certain all furnace cabinet or air handler doors/panels are tightly fastened.

A panel that isn’t tight may activate the safety switch, which stops power to the system.

Infrequently, an empty display can indicate you will need to get a new thermostat.

Heating and Cooling System Won’t Run

Check that your thermostat is set to “cool” or “heat,” not “off.”

During warm weather, confirm you set the thermostat lower than the current temperature. When it’s cool, confirm it’s higher. This sounds goofy, but we’ve seen it occur many times.

Make sure the power switch close to your indoor equipment is in the “on” position. You should also make sure the cabinet doors or panels are secure on your furnace cabinet or air handler. A loose panel can trip the safety switch, diverting power to the equipment.

Unit still won’t start? Confirm circuit breakers haven’t turned off and that your HVAC unit isn’t displaying error codes.

“Cool On” or “Heat On” is Flickering

To begin, make sure your thermostat is switched to “cool” or “heat.”

Then, ensure it’s signaling the appropriate equipment to run. This is typically shown by “cool on,” “heat on” or an icon.

If these words or the illustration is flashing, your thermostat is in a five-minute delay status. This mode keeps your system from damaging short cycling. This could take place if you lose power.

Honeywell Thermostat-Specific Error Codes

Honeywell Lyric™ T5 Wi-Fi (RCHT8612WF/RCHT9510WFW)

    • 164—Heat pump needs service. Call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for assistance.
    • 168—Wi-Fi radio error. Contact Lyric technical support at 800-633-3991. 170—Internal memory error. Call Lyric technical support at 800-633-3991.
    • 171—Set date and time. Finalize these settings so scheduling can occur.
    • 173—Thermostat temperature sensor error. Contact Lyric technical support at 800-633-3991.
    • 175—AC power restored. No action required.
    • 181/182—Put in a new air filter. Clear the screen by hitting “dismiss” after installing a new filter.
    • 184—Put in a new humidifier pad. Clear the display by touching “dismiss” after installing a clean pad filter.
    • 185—Replace dehumidifier filter. Clear the screen by tapping “dismiss” after installing a fresh filter.
    • 187—Rinse or install a new ventilator filter. Clear the screen by hitting “dismiss” after adding a new filter.
    • 188/189—Replace UV bulb. Ring Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for assistance.
    • 210—Register online for outside temperature. Download the Lyric app to complete this step and ensure accurate thermostat operation.
    • 388—Register online for remote access and outside temperature. Get the Lyric app to do this step and ensure proper thermostat operation.
    • 399—No Internet. Confirm your network settings.
    • 400—No Wi-Fi signal. Wait for the thermostat to reconnect or pick new Wi-Fi network.
    • 508—Wi-Fi not set up. Download the Lyric app and follow the steps to configure your thermostat.

For more specifics, view this thermostat’s user manual.

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005)

    • 164—Heat pump needs service. Call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for assistance.
    • 168—Wi-Fi radio error. Contact Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for help.
    • 170—Internal memory error. Call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for assistance.
    • 171—Set date and time. Finish these settings so scheduling can work.
    • 173—Thermostat temperature sensor error. Call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for help.
    • 175—AC power restored. No action required.
    • 177—Indoor temperature sensor error. Call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for support.
    • 178—Outdoor temperature sensor error. Contact Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for help.
    • 181/182—Replace air filter. Clear the display by hitting “dismiss” after putting in a fresh filter.
    • 183—Wash humidifier tank and replace water filter. Clear the screen by touching “dismiss” after finishing these steps.
    • 184—Replace humidifier pad. Clear the monitor by touching “dismiss” after installing pad filter.
    • 185—Install a new dehumidifier filter. Clear the thermostat by touching “dismiss” after putting in a clean filter.
    • 186—Clean ventilator core. Clear the display by hitting “dismiss” after finishing this task.
    • 187—Wash or install a new ventilator filter. Clear the display by tapping “dismiss” after getting a new filter.
    • 188/189—Add a new UV bulb. Contact Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for support.
    • 210—Register online for outside temperature. Use the Lyric app to complete this step and ensure accurate thermostat operation.
    • 388—Register online for remote access and outdoor temperature. Download the Lyric app to complete this step and ensure accurate thermostat operation.
    • 399—No Internet. Check your network settings.
    • 400—No Wi-Fi signal. Wait for the thermostat to reconnect or pick new Wi-Fi network.
    • 508—Wi-Fi not configured. Get the Lyric app and follow the process to connect your thermostat.

For more specifics, look at this thermostat’s user manual.

Our Experts are Ready to Provide Assistance

If you’re still experiencing problems after going through the troubleshooting steps, our professionals are here to support you. Call us at 866-397-3787 and we’ll be out quickly to determine the problem.

If you have an older thermostat, today is a fantastic time to think over a replacement. Thermostat technology has gotten better lately Ask us for more information on how smart thermostats can make your home comfier while helping save on heating and cooling expenses all year.

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