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 constantly updating its technology, bringing more features for your residence.

However, all thermostats can experience troubles every so often. As a result, we’ve prepared this valuable guidebook to walk you through troubleshooting. While Honeywell thermostat troubleshooting problems are rare, they happen.

While you can usually fix most thermostat troubles on your own, they sometimes need Expert assistance. Our HVAC Experts are here to help when you need us. We’re merely 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 typical dial-shaped thermostat. You won’t have error codes with this one, but it’s also the least efficient for lowering energy costs.
  • Programmable—This thermostat has a digital screen and arrows you press to set your desired temperature. You can also choose daily programs to decrease the temperature when you’re gone and set it higher when you get back.
  • Smart—You won’t have to set any programs on this thermostat, since it picks up on your routine. It intuitively raises and lowers the temperature when you or family members are gone to help you save on heating and cooling bills. You can also adjust the temperature anywhere via your phone or other Wi-Fi-enabled device.

As is the case with most technologically advanced things, there are common glitches that might take place. Many of these situations don’t need pro support and are simple to fix by yourself.

Common Honeywell Thermostat Troubleshooting Errors

All Honeywell thermostats have a special set of codes matching the malfunctions that occur.

Think how uncomplicated it can be to fix a computer by restarting it. Many times, diagnosing a thermostat can be just as easy.

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

Display is Blank

If the monitor is empty on your programmable thermostat, you may need to install new batteries. If that doesn’t take care of the problem or you rely on a smart thermostat, there might be a wiring malfunction.

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

In addition to that, you should make sure all furnace cabinet or air handler doors/panels are sturdily secured.

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

Less frequently, a blank monitor can indicate you need to install a new thermostat.

HVAC System Won’t Work

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

When it’s hot, make sure you set the thermostat below the room temperature. When it’s cold, make sure it’s higher. This sounds goofy, but we’ve seen it take place a lot of times.

Make sure the power switch near your indoor equipment is in the “on” position. You should also comfirm the cabinet doors or panels are closed on your furnace cabinet or air handler. An unsecured panel can trigger the safety switch, stopping electricity to the equipment.

Equipment still won’t start? Verify circuit breakers haven’t turned off and that your HVAC equipment isn’t experiencing error codes.

“Cool On” or “Heat On” is Flickering

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

Then, verify it’s telling the appropriate system to start. This is often demonstrated by “cool on,” “heat on” or a picture.

If these words or the picture is pulsing, your thermostat is in a five-minute delay mode. This mode stops your unit from harmful short cycling. This can happen if you lose power.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump needs 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. Finish these settings so scheduling can take place.
  • 173—Thermostat temperature sensor error. Reach Lyric technical support at 800-633-3991.
  • 175—AC power resumed. No action needed.
  • 181/182—Install a new air filter. Clear the display by tapping “dismiss” after installing a fresh filter.
  • 184—Replace humidifier pad. Clear the display by touching “dismiss” after installing a new pad filter.
  • 185—Put in a new dehumidifier filter. Clear the monitor by hitting “dismiss” after putting in a clean filter.
  • 187—Wash or put in a new ventilator filter. Clear the thermostat by tapping “dismiss” after installing a fresh filter.
  • 188/189—Replace UV bulb. Contact Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for support.
  • 210—Register online for outdoor temperature. Use the Lyric app to do this step and ensure accurate thermostat operation.
  • 388—Register online for remote access and outside temperature. Use the Lyric app to do 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 pick new Wi-Fi network.
  • 508—Wi-Fi not set up. Get the Lyric app and follow the steps to link your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005)

  • 164—Heat pump requires service. Contact Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for support.
  • 168—Wi-Fi radio error. Reach Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for assistance.
  • 170—Internal memory error. Reach Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for help.
  • 171—Set date and time. Complete these settings so scheduling can operate.
  • 173—Thermostat temperature sensor error. Call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for support.
  • 175—AC power restored. No action necessary.
  • 177—Indoor temperature sensor error. Reach Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for support.
  • 178—Outdoor temperature sensor error. Contact Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for assistance.
  • 181/182—Get a new air filter. Clear the screen by hitting “dismiss” after adding a fresh filter.
  • 183—Clean humidifier tank and replace water filter. Clear the display by touching “dismiss” after finishing these steps.
  • 184—Get a new humidifier pad. Clear the display by touching “dismiss” after adding a new pad filter.
  • 185—Replace dehumidifier filter. Clear the thermostat by tapping “dismiss” after putting in a fresh filter.
  • 186—Wash ventilator core. Clear the thermostat by tapping “dismiss” after completing this task.
  • 187—Wash or install a new ventilator filter. Clear the monitor by touching “dismiss” after buying a new filter.
  • 188/189—Add a new UV bulb. Contact Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for assistance.
  • 210—Register online for outdoor temperature. Use the Lyric app to finish this step and ensure correct thermostat operation.
  • 388—Register online for remote access and exterior temperature. Get the Lyric app to complete this step and ensure proper 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 set up. Get the Lyric app and follow the steps to connect your thermostat.

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

Our Experts are Available to Help

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

If you rely on an aging thermostat, now is a fantastic time to think over a new device. Thermostat technology has gotten better lately Ask us for more information on how smart thermostats can make your residence comfier while helping save on utility costs throughout the year.