How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the top thermostat brands, and we proudly install them on a usual basis in the U.S.. They’re long-lasting and dependable. Also, Honeywell is regularly improving its technology, offering more features for your house.

However, each thermostat can experience errors now and again. Due to this, we’ve put together this informative handbook to go over troubleshooting. While Honeywell thermostat troubleshooting problems are rare, they do pop up.

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

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

What Model of Thermostat Do I Have?

There are three types of thermostats:

    • Manual—This is the older dial-shaped thermostat. You won’t run into error codes with this one, but it’s also the least efficient for reducing energy expenses.
    • Programmable—This thermostat features a digital screen and arrows you use to determine your desired temperature. You can also set daily programs to decrease the temperature when you’re away and raise it when you come home.
    • Smart—You won’t have to schedule any programs on this thermostat, because it adjusts to your schedule. It automatically adjusts the temperature when you or loved ones are out and about to help you save on utility expenses. You can also adjust the temperature anywhere using your phone or other Wi-Fi-enabled device.

As is the case with many technologically advanced solutions, there are several glitches that might take place. Many of these troubles don’t need Expert support and are easy to fix alone.

Common Honeywell Thermostat Troubleshooting Problems

Each Honeywell thermostat has a special kind of codes matching the malfunctions that occur.

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

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

Display is Blank

If the monitor is clear on your programmable thermostat, you may need to put in new batteries. If that doesn’t take care of the problem or you have a smart thermostat, there may be a wiring issue.

Next, you should ensure the power is flowing for your furnace or air handler. Make sure the switch near the indoor unit is in the “on” position.

Also, you should confirm all furnace cabinet or air handler doors/panels are tightly secured.

A panel that isn’t tight may trigger the safety switch, which disconnects power to the equipment.

Less frequently, a clear monitor could signify you will need to install a new thermostat.

Comfort System Won’t Turn On

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

When it’s hot, verify you schedule the thermostat below the current temperature. When it’s cold, make sure it’s higher. This sounds absurd, but we’ve seen it take place many times.

Confirm the power switch near your indoor equipment is in the “on” position. You should also check the cabinet doors or panels are closed on your furnace cabinet or air handler. An unsecured panel can activate the safety switch, diverting current to the unit.

Unit still won’t start? Make sure circuit breakers haven’t flipped and that your HVAC system isn’t experiencing error codes.

“Cool On” or “Heat On” is Blinking

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

Then, verify it’s signaling the correct system to start. This is typically shown by “cool on,” “heat on” or an illustration.

If this set of words or the picture is flashing, your thermostat is in a five-minute delay mode. This mode protects your unit from harmful short cycling. This could happen if your power is interrupted.

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 support.
    • 168—Wi-Fi radio error. Contact Lyric technical support at 800-633-3991. 170—Internal memory error. Contact 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 restarted. No action required.
    • 181/182—Install a new air filter. Clear the monitor by touching “dismiss” after putting in a clean filter.
    • 184—Put in a new humidifier pad. Clear the thermostat by touching “dismiss” after putting in a clean pad filter.
    • 185—Replace dehumidifier filter. Clear the display by hitting “dismiss” after installing a clean filter.
    • 187—Wash or install a new ventilator filter. Clear the screen by hitting “dismiss” after installing a fresh filter.
    • 188/189—Install a new UV bulb. Ring Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for assistance.
    • 210—Register online for exterior temperature. Use the Lyric app to complete this step and ensure proper thermostat operation.
    • 388—Register online for remote access and outside temperature. Download the Lyric app to complete this step and ensure correct thermostat operation.
    • 399—No Internet. Verify 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 steps to configure your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005)

    • 164—Heat pump needs service. Contact Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for help.
    • 168—Wi-Fi radio error. Reach Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for support.
    • 170—Internal memory error. Contact 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 assistance.
    • 175—AC power reconnected. No action needed.
    • 177—Indoor temperature sensor error. Call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for assistance.
    • 178—Outdoor temperature sensor error. Contact 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 putting in a new filter.
    • 183—Rinse humidifier tank and add a new water filter. Clear the display by tapping “dismiss” after finishing these steps.
    • 184—Install a new humidifier pad. Clear the screen by hitting “dismiss” after getting a new pad filter.
    • 185—Replace dehumidifier filter. Clear the display by touching “dismiss” after installing a fresh filter.
    • 186—Clean ventilator core. Clear the display by tapping “dismiss” after completing this task.
    • 187—Rinse or get a new ventilator filter. Clear the monitor by tapping “dismiss” after installing 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 support.
    • 210—Register online for outside temperature. Use the Lyric app to do this step and ensure proper thermostat operation.
    • 388—Register online for remote access and exterior temperature. Use the Lyric app to complete this step and ensure correct thermostat operation.
    • 399—No Internet. Check your network settings.
    • 400—No Wi-Fi signal. Wait for the thermostat to reconnect or choose new Wi-Fi network.
    • 508—Wi-Fi not set up. Download the Lyric app and follow the procedures to connect your thermostat.

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

Our Experts are Ready to Help

If you’re still having problems after working through the troubleshooting steps, our professionals are ready to help. Give us a call at 866-397-3787 and we’ll arrive rapidly to diagnose the issue.

If you rely on a dated thermostat, today is a great time to think over a new thermostat. Thermostat technology has advanced lately Ask us for more details on how smart thermostats can make your residence more comfortable while helping save on heating and cooling costs all year.

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