How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the leading thermostat brands, and we proudly install them on a usual basis in the U.S.. They’re long-lasting and reliable. Plus, Honeywell is frequently enhancing its technology, resulting in more features for your home.

Nevertheless, all thermostats can have issues from time to time. As a result, we’ve prepared this valuable handbook to run through troubleshooting. While Honeywell thermostat troubleshooting problems are rare, they happen.

While you can typically solve most thermostat issues by yourself, they sometimes call for Expert support. Our home comfort professionals are here to assist you when you need us. We’re just a call away at 866-397-3787.

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

What Model of Thermostat Do I Have?

There are three models of thermostats:

  • Manual—This is the typical dial-shaped thermostat. You won’t experience error codes with this one, but it’s also the least efficient for saving on utility bills.
  • Programmable—This thermostat features a digital screen and arrows you use to set your desired temperature. You can also choose daily programs to lower the temperature when you’re at work and raise it when you come home.
  • Smart—You won’t have to make any programs on this thermostat, since it picks up on your routine. It intuitively raises and lowers the temperature when you or loved ones are gone to help you save on heating and cooling expenses. You can also adjust the temperature anywhere using your phone or other Wi-Fi-enabled device.

As you know most technologically advanced things, there are several malfunctions that can occur. Many of these issues don’t require pro assistance and are easy to solve on your own.

Common Honeywell Thermostat Troubleshooting Errors

All Honeywell thermostats have a unique set of codes matching the malfunctions that take place.

Think how uncomplicated it can be to repair a computer by restarting it. Many times, correcting a thermostat can be just as simple.

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

Display is Blank

If the screen is blank on your programmable thermostat, you could need to put in new batteries. If that doesn’t fix the problem or you rely on a smart thermostat, there may be a wiring problem.

Next, you should ensure the power is on for your furnace or air handler. Confirm the switch by the indoor system is in the “on” position.

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

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

While it’s less common, a blank monitor might signify you should get a new thermostat.

Comfort Unit Won’t Turn On

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

During warm weather, confirm you schedule the thermostat below the current temperature. In the winter, verify it’s higher. This sounds silly, but we’ve seen it take place a lot of times.

Make sure the power switch by your indoor equipment is in the “on” position. You should also comfirm the cabinet doors or panels are secure on your furnace cabinet or air handler. A loose panel can trip the safety switch, diverting power to the equipment.

Unit still won’t turn on? Verify circuit breakers haven’t flipped and that your HVAC system isn’t displaying error codes.

“Cool On” or “Heat On” is Blinking

To start, verify your thermostat is switched to “cool” or “heat.”

Then, ensure it’s calling for the appropriate system to run. This is usually demonstrated by “cool on,” “heat on” or an illustration.

If these words or the picture is pulsing, your thermostat is in a five-minute delay state. This setting protects your equipment from damaging short cycling. This can take place if you lose electricity.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump must be serviced. Call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for assistance.
  • 168—Wi-Fi radio error. Reach 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 run.
  • 173—Thermostat temperature sensor error. Reach Lyric technical support at 800-633-3991.
  • 175—AC power restarted. No action needed.
  • 181/182—Put in a new air filter. Clear the monitor by tapping “dismiss” after installing a clean filter.
  • 184—Install a new humidifier pad. Clear the screen by tapping “dismiss” after putting in a fresh pad filter.
  • 185—Put in a new dehumidifier filter. Clear the display by tapping “dismiss” after putting in a fresh filter.
  • 187—Wash or put in a new ventilator filter. Clear the screen by touching “dismiss” after putting in a clean 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 outside temperature. Download the Lyric app to finish this step and ensure proper thermostat operation.
  • 388—Register online for remote access and exterior temperature. Download the Lyric app to do 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 choose new Wi-Fi network.
  • 508—Wi-Fi not set. Use the Lyric app and follow the process to configure your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005)

  • 164—Heat pump requires service. Call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for assistance.
  • 168—Wi-Fi radio error. Contact Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for help.
  • 170—Internal memory error. Contact Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for assistance.
  • 171—Set date and time. Finish these settings so scheduling can operate.
  • 173—Thermostat temperature sensor error. Call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for assistance.
  • 175—AC power resumed. 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. Reach Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for help.
  • 181/182—Get a new air filter. Clear the screen by hitting “dismiss” after installing a clean filter.
  • 183—Clean humidifier tank and add a new water filter. Clear the monitor by touching “dismiss” after completing these tasks.
  • 184—Get a new humidifier pad. Clear the monitor by touching “dismiss” after adding a new pad filter.
  • 185—Install a new dehumidifier filter. Clear the display by touching “dismiss” after adding a fresh filter.
  • 186—Rinse ventilator core. Clear the screen by tapping “dismiss” after doing this task.
  • 187—Wash or install a new ventilator filter. Clear the display by tapping “dismiss” after getting 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 outdoor temperature. Use the Lyric app to finish this step and ensure accurate thermostat operation.
  • 388—Register online for remote access and outside temperature. Download the Lyric app to do 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 procedures to connect your thermostat.

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

Our Experts are Available to Provide Support

If you’re still having issues after working through the troubleshooting steps, our Experts are ready to assist you. Call us at 866-397-3787 and we’ll come to your house as fast as we can to determine the problem.

If you rely on an aging thermostat, today is a fantastic time to think about a new device. Thermostat technology has advanced lately Ask us for more information on how smart thermostats can make your home more comfortable while helping save on heating and cooling expenses throughout the year.