How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the top thermostat brands, and we proudly install them on a regular basis in the U.S.. They’re sturdy and dependable. Plus, Honeywell is regularly advancing its technology, offering more features for your residence.

Nevertheless, all thermostats can run into issues every now and then. As a result, we’ve prepared this informative handbook to walk you through troubleshooting. While Honeywell thermostat troubleshooting problems are rare, they happen.

While you can typically solve many thermostat troubles alone, they occasionally require Expert support. Our heating and cooling Experts are available to assist you when you need us. We’re merely a call away at 866-397-3787.

Let’s begin the process by figuring out what model of thermostat your residence has.

What Type of Thermostat Do I Have?

There are three types of thermostats:

    • Manual—This is the older dial-shaped thermostat. You won’t experience error codes with this type, but it’s also the least efficient for lowering heating and cooling bills.
    • 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 gone and increase it when you return.
    • Smart—You won’t have to schedule any programs on this thermostat, since it picks up on your day. It intuitively changes the temperature when you or loved ones are out and about to help you save on utility expenses. You can also raise or lower the temperature anywhere using your phone or other Wi-Fi-enabled device.

As is the case with most technologically advanced solutions, there are common malfunctions that can take place. Many of these problems don’t call for pro support and are easy to solve alone.

Common Honeywell Thermostat Troubleshooting Problems

Every Honeywell thermostat has a unique kind of codes assigned to the issues that take place.

Think how uncomplicated it can be to repair a computer by restarting it. In most cases, troubleshooting a thermostat can be just as easy.

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

Display is Blank

If the display is clear on your programmable thermostat, you might need to install new batteries. If that doesn’t solve the malfunction or you have a smart thermostat, there might be a wiring issue.

Next, you should check the power is enabled for your furnace or air handler. Make sure the switch close to the indoor equipment is in the “on” position.

In addition to that, you should make sure all furnace cabinet or air handler doors/panels are sturdily secured.

An unsecured panel may trigger the safety switch, which disconnects power to the unit.

Infrequently, a clear screen may mean you should get a new thermostat.

Comfort System Won’t Run

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

In the summer, make sure you set the thermostat lower than the room temperature. When it’s cold, confirm it’s higher. This sounds silly, but we’ve seen it happen a lot of times.

Ensure the power switch near your indoor unit is in the “on” position. You should also comfirm the cabinet doors or panels are closed on your furnace cabinet or air handler. A loose panel can trigger the safety switch, stopping power to the system.

Equipment still won’t run? Make sure circuit breakers haven’t turned off and that your HVAC unit isn’t experiencing error codes.

“Cool On” or “Heat On” is Flashing

First, check your thermostat is switched to “cool” or “heat.”

Then, ensure it’s calling for the right system to start. This is usually shown by “cool on,” “heat on” or a picture.

If this set of words or the icon is blinking, your thermostat is in a five-minute delay status. This mode stops your unit from bad short cycling. This can take place if your power is interrupted.

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 support.
    • 168—Wi-Fi radio error. Reach 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 take place.
    • 173—Thermostat temperature sensor error. Call Lyric technical support at 800-633-3991.
    • 175—AC power restored. No action needed.
    • 181/182—Put in a new air filter. Clear the monitor by touching “dismiss” after adding a new filter.
    • 184—Install a new humidifier pad. Clear the monitor by tapping “dismiss” after adding a clean pad filter.
    • 185—Install a new dehumidifier filter. Clear the display by hitting “dismiss” after putting in a fresh filter.
    • 187—Wash or replace ventilator filter. Clear the screen by touching “dismiss” after putting in a fresh filter.
    • 188/189—Replace UV bulb. Ring Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for support.
    • 210—Register online for exterior temperature. Use the Lyric app to do this step and ensure accurate thermostat operation.
    • 388—Register online for remote access and outside temperature. Use 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. Get the Lyric app and follow the steps to connect your thermostat.

For more specifics, see 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 support.
    • 168—Wi-Fi radio error. Contact Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for assistance.
    • 170—Internal memory error. Reach Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for help.
    • 171—Set date and time. Finish 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 reconnected. No action necessary.
    • 177—Indoor temperature sensor error. Contact Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for support.
    • 178—Outdoor temperature sensor error. Call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for help.
    • 181/182—Get a new air filter. Clear the thermostat by tapping “dismiss” after adding a new filter.
    • 183—Wash humidifier tank and add a new water filter. Clear the display by touching “dismiss” after doing these tasks.
    • 184—Replace humidifier pad. Clear the display by tapping “dismiss” after installing pad filter.
    • 185—Get a new dehumidifier filter. Clear the display by touching “dismiss” after installing a clean filter.
    • 186—Clean ventilator core. Clear the display by tapping “dismiss” after completing this task.
    • 187—Clean or install a new ventilator filter. Clear the display by tapping “dismiss” after getting a new filter.
    • 188/189—Install a new UV bulb. Get in touch with Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for support.
    • 210—Register online for exterior temperature. Download the Lyric app to do this step and ensure proper thermostat operation.
    • 388—Register online for remote access and exterior temperature. Get the Lyric app to complete 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 select new Wi-Fi network.
    • 508—Wi-Fi not set up. Download the Lyric app and follow the process to connect your thermostat.

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

Our Experts are Here to Help

If you’re still having issues after trying the troubleshooting steps, our professionals are here to help. Call us at 866-397-3787 and we’ll arrive rapidly to figure out the malfunction.

If you rely on an older thermostat, today is a fantastic time to think over a new thermostat. Thermostat technology has come a long way in recent years Ask us for more details on how smart thermostats can make your house more comfortable while helping save on heating and cooling expenses throughout the year.

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