How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the top thermostat manufacturers, and we proudly install them on a regular basis in Charlotte. They’re durable and dependable. Also, Honeywell is frequently enhancing its technology, resulting in more features for your residence.

Still, each thermostat can have issues every now and then. As a result, we’ve prepared this valuable guide to run through troubleshooting.

While you can typically fix many thermostat issues by yourself, they often call for Expert assistance. Our heating and cooling pros are here to help when you need us. We’re just a call away at 704-705-8135.

Let’s begin the process by finding out what model of thermostat your residence 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 have error codes with this one, but it’s also the least efficient for lowering utility bills.
  • Programmable—This thermostat has a digital screen and arrows you use to determine your desired temperature. You can also choose daily programs to lower the temperature when you’re away and set it higher when you get back.
  • Smart—You won’t have to set any programs on this thermostat, since it learns your schedule. It instinctively raises and lowers the temperature when you or family members are away to help you save on heating and cooling expenses. You can also adjust the temperature anywhere on your phone or other Wi-Fi-enabled device. 

As you’re aware the majority of technologically advanced things, there are several problems that may take place. Most of these situations don’t require Expert assistance and are uncomplicated enough to solve on your own.

Common Honeywell Thermostat Problems

Every thermostat has a special kind of codes that correspond to the issues that occur.

Think how uncomplicated it can be to fix a computer by restarting it. In many instances, troubleshooting a thermostat can be just as simple.

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

Display is Blank

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

Next, you should make sure the power is on for your furnace or air handler. Verify 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 tightly in place.

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

Infrequently, a clear display may mean you should install a new thermostat.

Heating and Cooling Unit Won’t Run

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

During warm weather, make sure you set the thermostat lower than the current temperature. When it’s cold, verify it’s higher. This sounds absurd, but we’ve seen it take place many times.

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

Heating or cooling still won’t start? Make sure circuit breakers haven’t tripped and that your HVAC unit isn’t showing error codes.

“Cool On” or “Heat On” is Flashing

To begin, verify your thermostat is set to “cool” or “heat.”

Then, make sure it’s telling the right equipment to turn on. This is typically demonstrated by “cool on,” “heat on” or an icon.

If this phrase or the picture is flashing, your thermostat is in a five-minute delay status. This feature keeps your equipment from bad short cycling. This can occur if you lose electricity.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump must be serviced. Call Komfort Air at 704-705-8135 for support.
  • 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. Complete these settings so scheduling can occur.
  • 173—Thermostat temperature sensor error. Call Lyric technical support at 800-633-3991.
  • 175—AC power resumed. No action required.
  • 181/182—Replace air filter. Clear the screen by tapping “dismiss” after installing a new filter.
  • 184—Put in a new humidifier pad. Clear the thermostat by hitting “dismiss” after putting in a fresh pad filter.
  • 185—Put in a new dehumidifier filter. Clear the monitor by tapping “dismiss” after adding a fresh filter.
  • 187—Rinse or install a new ventilator filter. Clear the thermostat by touching “dismiss” after installing a clean filter.
  • 188/189—Replace UV bulb. Ring Komfort Air at 704-705-8135 for help.
  • 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. Get the Lyric app to do this step and ensure proper 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. Download the Lyric app and follow the steps to configure your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump must be serviced service. Reach Komfort Air at 704-705-8135 for help.
  • 168—Wi-Fi radio error. Contact Komfort Air at 704-705-8135 for support.
  • 170—Internal memory error. Contact Komfort Air at 704-705-8135 for help.
  • 171—Set date and time. Complete these settings so scheduling can run.
  • 173—Thermostat temperature sensor error. Reach Komfort Air at 704-705-8135 for assistance.
  • 175—AC power restored. No action required.
  • 177—Indoor temperature sensor error. Reach Komfort Air at 704-705-8135 for support.
  • 178—Outdoor temperature sensor error. Contact Komfort Air at 704-705-8135 for assistance.
  • 181/182—Install a new air filter. Clear the display by touching “dismiss” after adding a new filter.
  • 183—Rinse humidifier tank and install a new water filter. Clear the monitor by tapping “dismiss” after completing these tasks.
  • 184—Replace humidifier pad. Clear the monitor by tapping “dismiss” after getting a new pad filter.
  • 185—Install a new dehumidifier filter. Clear the screen by tapping “dismiss” after putting in a new filter.
  • 186—Rinse ventilator core. Clear the thermostat by hitting “dismiss” after completing this task.
  • 187—Rinse or replace ventilator filter. Clear the monitor by touching “dismiss” after installing a new filter.
  • 188/189—Install a new UV bulb. Reach Komfort Air at 704-705-8135 for support.
  • 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 outside temperature. Get 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 choose new Wi-Fi network.
  • 508—Wi-Fi not connected. Get the Lyric app and follow the steps to connect your thermostat.

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

Our Experts are Ready to Provide Support

If you’re still experiencing problems after going through the troubleshooting list, our professionals are here to help. Reach us at 704-705-8135 and we’ll come to your house rapidly to determine the malfunction.

If you rely on an older thermostat, today is a fantastic time to think over a new device. Thermostat technology has advanced lately Ask us for more details on how smart thermostats can make your home more comfortable while helping save on energy costs year-round.

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