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 long-lasting and trustworthy. In addition, Honeywell is regularly advancing its technology, offering more features for your residence.

Still, every thermostat can have problems occasionally. Due to this, we’ve put together this informative handbook to walk you through troubleshooting. While Honeywell thermostat troubleshooting problems are rare, they do occur.

While you can usually repair the majority of thermostat problems by yourself, they sometimes need Expert support. Our heating and cooling pros are here to help when you need us. We’re only a call away at 866-397-3787.

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

What Type of Thermostat Do I Have?

There are three kinds 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 bills.
    • Programmable—This thermostat features a digital screen and arrows you press to determine your desired temperature. You can also choose 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 picks up on your routine. It intuitively adjusts the temperature when you or family members are out and about to help you save on energy bills. You can also change the temperature anywhere via your phone or other Wi-Fi-enabled device.

As you’re aware many technologically advanced products, there are regular problems that may take place. The majority of of these problems don’t require pro help and are easy to repair by yourself.

Common Honeywell Thermostat Troubleshooting Issues

Every Honeywell thermostat has an exclusive group of codes that correspond to the glitches that occur.

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

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

Display is Blank

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

Next, you should ensure the power is flowing for your furnace or air handler. Confirm the switch by 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 tightly in place.

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

While it’s less common, a clear screen can mean you should install a new thermostat.

Comfort Unit Won’t Start

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

When it’s hot, make sure you put the thermostat beneath the room temperature. When it’s cool, make sure it’s higher. This sounds silly, but we’ve seen it take place lots of times.

Confirm the power switch close to your indoor system is in the “on” position. You should also comfirm the cabinet doors or panels are tight on your furnace cabinet or air handler. An open panel can trip the safety switch, cutting off electricity to the unit.

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

“Cool On” or “Heat On” is Blinking

First, confirm your thermostat is on “cool” or “heat.”

Then, check it’s telling the correct unit to turn on. This is typically shown by “cool on,” “heat on” or a picture.

If this phrase or the picture is blinking, your thermostat is in a five-minute delay status. This feature keeps your system from bad short cycling. This can 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 assistance.
    • 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. Finish 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 necessary.
    • 181/182—Install a new air filter. Clear the monitor by hitting “dismiss” after adding a fresh filter.
    • 184—Install a new humidifier pad. Clear the monitor by hitting “dismiss” after adding a new pad filter.
    • 185—Replace dehumidifier filter. Clear the screen by hitting “dismiss” after adding a clean filter.
    • 187—Clean or put in a new ventilator filter. Clear the screen by touching “dismiss” after adding a fresh filter.
    • 188/189—Replace UV bulb. Contact Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for help.
    • 210—Register online for outside temperature. Use the Lyric app to finish this step and ensure accurate thermostat operation.
    • 388—Register online for remote access and exterior temperature. Get the Lyric app to complete this step and ensure accurate 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. Get the Lyric app and follow the procedure to link your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005)

    • 164—Heat pump must be serviced service. Call 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 help.
    • 170—Internal memory error. Call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for support.
    • 171—Set date and time. Complete these settings so scheduling can work.
    • 173—Thermostat temperature sensor error. Call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for assistance.
    • 175—AC power reconnected. No action required.
    • 177—Indoor temperature sensor error. Reach 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 assistance.
    • 181/182—Install a new air filter. Clear the screen by hitting “dismiss” after putting in a new filter.
    • 183—Clean humidifier tank and replace water filter. Clear the display by hitting “dismiss” after finishing these tasks.
    • 184—Get a new humidifier pad. Clear the display by hitting “dismiss” after adding a new pad filter.
    • 185—Get a new dehumidifier filter. Clear the thermostat by touching “dismiss” after putting in a clean filter.
    • 186—Rinse ventilator core. Clear the screen by touching “dismiss” after finishing this task.
    • 187—Rinse or replace ventilator filter. Clear the screen by tapping “dismiss” after buying a new filter.
    • 188/189—Get a new UV bulb. Reach Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for support.
    • 210—Register online for outside temperature. Download the Lyric app to finish this step and ensure correct thermostat operation.
    • 388—Register online for remote access and outside temperature. Get the Lyric app to finish this step and ensure proper 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. Get the Lyric app and follow the process to connect your thermostat.

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

Our Experts are Ready to Help

If you’re still having troubles after trying the troubleshooting list, our pros are here to help. Reach us at 866-397-3787 and we’ll be out as fast as we can to diagnose the issue.

If you have an aging thermostat, right now is a great time to think about a replacement. Thermostat technology has gotten better lately Ask us for more info on how smart thermostats can make your house more comfortable while helping save on utility costs throughout the year.

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