How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the best thermostat brands, and we proudly install them on a regular basis in the U.S.. They’re sturdy and dependable. Also, Honeywell is frequently updating its technology, offering more features for your family.

Nevertheless, all thermostats can have errors from time to time. That’s why we’ve put together this valuable manual to go over troubleshooting. While Honeywell thermostat troubleshooting problems are rare, they do occur.

While you can typically fix the majority of thermostat problems on your own, they often call for Expert assistance. Our HVAC pros are ready to help 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 type of thermostat your residence has.

What Kind of Thermostat Do I Have?

There are three types of thermostats:

    • Manual—This is the typical dial-shaped thermostat. You won’t have error codes with this type, but it’s also the least efficient for reducing energy expenses.
    • Programmable—This thermostat has 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 at work and raise it when you get back.
    • Smart—You won’t have to set any programs on this thermostat, since it learns your schedule. It intuitively raises and lowers the temperature when you or loved ones are out and about to help you save on utility costs. You can also raise or lower the temperature anywhere using your phone or other Wi-Fi-enabled device.

As you know most technologically advanced solutions, there are several problems that might take place. Most of these troubles don’t call for Expert support and are simple to repair on your own.

Common Honeywell Thermostat Troubleshooting Issues

All Honeywell thermostats have a special set of codes that correspond to the glitches that occur.

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

Here is a listing the most encountered Honeywell thermostat problems. These are applicable 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 problem or you have a smart thermostat, there could be a wiring problem.

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

Additionally, you should make certain all furnace cabinet or air handler doors/panels are securely secured.

A loose panel may activate the safety switch, which disconnects power to the equipment.

While it’s less common, a blank screen may mean you will need to get a new thermostat.

HVAC System Won’t Start

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

During warm weather, confirm you set the thermostat beneath the current temperature. When it’s cool, confirm it’s higher. This sounds silly, but we’ve seen it happen a lot of times.

Ensure the power switch by your indoor equipment is in the “on” position. You should also check the cabinet doors or panels are tight on your furnace cabinet or air handler. An unsecured panel can trigger the safety switch, diverting power to the equipment.

Heating or cooling still won’t run? Verify circuit breakers haven’t turned off and that your HVAC equipment isn’t showing error codes.

“Cool On” or “Heat On” is Flickering

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

Then, ensure it’s telling the right unit to run. This is usually shown by “cool on,” “heat on” or a picture.

If these words or the icon is blinking, your thermostat is in a five-minute delay status. This feature keeps your system from harmful short cycling. This may 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 help.
    • 168—Wi-Fi radio error. Call 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 run.
    • 173—Thermostat temperature sensor error. Contact Lyric technical support at 800-633-3991.
    • 175—AC power restored. No action needed.
    • 181/182—Replace air filter. Clear the screen by touching “dismiss” after putting in a clean filter.
    • 184—Install a new humidifier pad. Clear the monitor by hitting “dismiss” after putting in a new pad filter.
    • 185—Put in a new dehumidifier filter. Clear the screen by hitting “dismiss” after adding a fresh filter.
    • 187—Rinse or put in a new ventilator filter. Clear the screen by touching “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. Use the Lyric app to do this step and ensure correct thermostat operation.
    • 388—Register online for remote access and exterior temperature. Get the Lyric app to do this step and ensure accurate 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 configured. Use the Lyric app and follow the steps to link your thermostat.

For more information, 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 help.
    • 168—Wi-Fi radio error. Contact Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for support.
    • 170—Internal memory error. Call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for assistance.
    • 171—Set date and time. Complete these settings so scheduling can operate.
    • 173—Thermostat temperature sensor error. Contact Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for assistance.
    • 175—AC power restored. No action required.
    • 177—Indoor temperature sensor error. Reach Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for help.
    • 178—Outdoor temperature sensor error. Reach Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for assistance.
    • 181/182—Install a new air filter. Clear the monitor by touching “dismiss” after adding a new filter.
    • 183—Rinse humidifier tank and replace water filter. Clear the display by tapping “dismiss” after finishing these tasks.
    • 184—Replace humidifier pad. Clear the monitor by touching “dismiss” after adding a new pad filter.
    • 185—Install a new dehumidifier filter. Clear the thermostat by tapping “dismiss” after putting in a clean filter.
    • 186—Rinse ventilator core. Clear the thermostat by tapping “dismiss” after finishing this task.
    • 187—Clean or replace ventilator filter. Clear the screen 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 assistance.
    • 210—Register online for outside temperature. Use the Lyric app to finish this step and ensure correct 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. Verify your network settings.
    • 400—No Wi-Fi signal. Wait for the thermostat to reconnect or pick new Wi-Fi network.
    • 508—Wi-Fi not connected. Use the Lyric app and follow the procedures to connect your thermostat.

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

Our Experts are Ready to Provide Assistance

If you’re still experiencing troubles after going through the troubleshooting steps, our pros are ready to help. Reach us at 866-397-3787 and we’ll arrive rapidly to determine the issue.

If you rely on an older thermostat, now is a fantastic time to think about a new thermostat. Thermostat technology has advanced in recent years Ask us for more information on how smart thermostats can make your residence more convenient while helping save on energy expenses all year.

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