How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the best thermostat producers, and we proudly install them on a usual basis in the U.S.. They’re sturdy and reliable. Plus, Honeywell is regularly updating its technology, offering more features for your residence.

However, all thermostats can run into problems now and then. Due to this, we’ve put together this helpful guidebook to walk you through troubleshooting. While Honeywell thermostat troubleshooting problems are rare, they happen.

While you can typically repair the majority of thermostat issues alone, they often require Expert assistance. Our home comfort professionals are available to assist you when you need us. We’re merely a call away at 866-397-3787.

Let’s get started with the process by figuring out what kind 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 run into error codes with this kind, but it’s also the least efficient for reducing heating and cooling costs.
    • Programmable—This thermostat includes a digital screen and arrows you touch to set your desired temperature. You can also use daily programs to decrease the temperature when you’re away and increase it when you get back.
    • Smart—You won’t have to make any programs on this thermostat, as it learns your schedule. It intuitively adjusts the temperature when you or family members are gone to help you save on utility expenses. You can also adjust the temperature anywhere via your phone or other Wi-Fi-enabled device.

As is the case with many technologically advanced solutions, there are several glitches that may happen. Most of these troubles don’t need Expert assistance and are uncomplicated enough to fix alone.

Common Honeywell Thermostat Troubleshooting Errors

All Honeywell thermostats have a special group of codes that correspond to the problems that take place.

Think how easy it can be to restore a computer by restarting it. For the most part, diagnosing a thermostat can be just as uncomplicated.

Here is a guide to the most reported Honeywell thermostat errors. These involve the following programmable thermostats:

Display is Blank

If the display is empty on your programmable thermostat, you could need to put in new batteries. If that doesn’t fix the malfunction or you have a smart thermostat, there might be a wiring problem.

Next, you should ensure the power is flowing for your furnace or air handler. Confirm the switch close to the indoor equipment is in the “on” position.

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

An unsecured panel may trigger the safety switch, which stops power to the system.

Less frequently, a clear display can mean you will need to install a new thermostat.

Heating and Cooling System Won’t Work

Make sure that your thermostat is on “cool” or “heat,” not “off.”

During warm weather, confirm you set the thermostat beneath the ambient temperature. When it’s cold, make sure it’s higher. This sounds absurd, but we’ve seen it happen lots of times.

Make sure the power switch by your indoor system is in the “on” position. You should also comfirm the cabinet doors or panels are secure on your furnace cabinet or air handler. An open panel can trip the safety switch, diverting electricity to the system.

System still won’t run? Verify circuit breakers haven’t turned off and that your HVAC system isn’t showing error codes.

“Cool On” or “Heat On” is Flickering

To start, ensure your thermostat is set to “cool” or “heat.”

Then, check it’s telling the appropriate unit to run. This is usually indicated by “cool on,” “heat on” or a picture.

If these words or the icon is flashing, your thermostat is in a five-minute delay status. This setting keeps your system from damaging short cycling. This could occur if you lose electricity.

Honeywell Thermostat-Specific Error Codes

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

    • 164—Heat pump requires service. Call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for help.
    • 168—Wi-Fi radio error. Call Lyric technical support at 800-633-3991. 170—Internal memory error. Reach Lyric technical support at 800-633-3991.
    • 171—Set date and time. Finalize these settings so scheduling can take place.
    • 173—Thermostat temperature sensor error. Call Lyric technical support at 800-633-3991.
    • 175—AC power resumed. No action required.
    • 181/182—Install a new air filter. Clear the display by hitting “dismiss” after putting in a fresh filter.
    • 184—Install a new humidifier pad. Clear the screen by tapping “dismiss” after adding a new pad filter.
    • 185—Install a new dehumidifier filter. Clear the screen by touching “dismiss” after installing a clean filter.
    • 187—Clean or install a new ventilator filter. Clear the screen by touching “dismiss” after installing a new filter.
    • 188/189—Replace UV bulb. Call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for assistance.
    • 210—Register online for outdoor temperature. Get the Lyric app to finish this step and ensure proper thermostat operation.
    • 388—Register online for remote access and outside temperature. Download the Lyric app to finish 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 select new Wi-Fi network.
    • 508—Wi-Fi not configured. Use the Lyric app and follow the process to configure your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005)

    • 164—Heat pump requires service. Reach Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for assistance.
    • 168—Wi-Fi radio error. Call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for assistance.
    • 170—Internal memory error. Call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for assistance.
    • 171—Set date and time. Finalize these settings so scheduling can run.
    • 173—Thermostat temperature sensor error. Call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for help.
    • 175—AC power restored. No action needed.
    • 177—Indoor temperature sensor error. Contact Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for support.
    • 178—Outdoor temperature sensor error. Reach Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for assistance.
    • 181/182—Replace air filter. Clear the screen by hitting “dismiss” after adding a new filter.
    • 183—Wash humidifier tank and add a new water filter. Clear the monitor by touching “dismiss” after doing these procedures.
    • 184—Get a new humidifier pad. Clear the screen by touching “dismiss” after getting a new pad filter.
    • 185—Replace dehumidifier filter. Clear the thermostat by tapping “dismiss” after installing a clean filter.
    • 186—Clean ventilator core. Clear the display by touching “dismiss” after doing this task.
    • 187—Wash or get a new ventilator filter. Clear the display by touching “dismiss” after buying a new filter.
    • 188/189—Get a new UV bulb. Get in touch with Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for help.
    • 210—Register online for exterior temperature. Download the Lyric app to finish this step and ensure accurate thermostat operation.
    • 388—Register online for remote access and exterior temperature. Download the Lyric app to finish this step and ensure correct 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. Get the Lyric app and follow the procedures to connect your thermostat.

For more details, check this thermostat’s user manual.

Our Experts are Ready to Help

If you’re still running into troubles after going through the troubleshooting list, our Experts are ready to support you. Call us at 866-397-3787 and we’ll come to your house as fast as we can to diagnose the problem.

If you have an aging thermostat, right now is a good time to think about a new device. Thermostat technology has gotten better lately Ask us for more details on how smart thermostats can make your house comfier while helping save on energy bills all year.

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