How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the leading thermostat brands, and we proudly install them on a regular basis in Windsor. They’re sturdy and trustworthy. Plus, Honeywell is regularly improving its technology, bringing more features for your family.

However, each thermostat can run into problems every so often. That’s why we’ve put together this valuable manual to run through troubleshooting. While Honeywell thermostat problems are rare, they happen. 

While you can often solve most thermostat troubles by yourself, they occasionally require Expert help. Our HVAC professionals are available to assist you when you need us. We’re just a call away at 226-773-3357.

Let’s start the process by determining what type of thermostat your residence has.

What Type of Thermostat Do I Have?

There are three models of thermostats:

  • Manual—This is the classic dial-shaped thermostat. You won’t experience 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 touch to choose your desired temperature. You can also choose daily programs to decrease the temperature when you’re at work and raise it when you get back.
  • Smart—You won’t have to make any programs on this thermostat, since it adjusts to your routine. It intuitively adjusts the temperature when you or family members are gone to help you save on utility expenses. You can also adjust the temperature anywhere on your phone or other Wi-Fi-enabled device. 

As you know many technologically advanced solutions, there are several problems that may take place. The majority of of these situations don’t need Expert support and are easy to solve by yourself.

Common Honeywell Thermostat Problems

Each thermostat has a unique set of codes that correspond to the glitches that happen.

Think how uncomplicated it can be to fix a computer by restarting it. In most cases, troubleshooting a thermostat can be just as easy.

Here are some of the most encountered Honeywell thermostat problems. These are applicable to the following programmable thermostats:

Display is Blank

If the screen is clear on your programmable thermostat, you could need to get new batteries. If that doesn’t fix the issue or you have a smart thermostat, there may be a wiring issue.

Next, you should ensure the power is on for your furnace or air handler. Make sure the switch near the indoor unit is switched “up”.

Also, you should confirm all furnace cabinet or air handler doors/panels are securely fastened.

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

Less frequently, a blank display can signify you should install a new thermostat.

Comfort Equipment Won’t Turn On

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

During warm weather, verify you put the thermostat below the current temperature. When it’s cold, make sure it’s higher. This sounds silly, but we’ve seen it occur many times.

Confirm the power switch close to your indoor unit 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 trigger the safety switch, cutting off power to the equipment.

System still won’t start? Make sure circuit breakers haven’t tripped and that your HVAC system isn’t displaying error codes.

“Cool On” or “Heat On” is Flashing

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

Then, ensure it’s signaling the correct system to turn on. This is often indicated by “cool on,” “heat on” or an icon.

If these words or the picture is blinking, your thermostat is in a five-minute delay status. This setting keeps your equipment from harmful short cycling. This can occur if you lose electricity.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump requires service. Call Bryant Heating & Cooling Service Experts at 226-773-3357 for support.
  • 168—Wi-Fi radio error. Contact 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—Install a new air filter. Clear the screen by tapping “dismiss” after installing a clean filter.
  • 184—Replace humidifier pad. Clear the monitor by tapping “dismiss” after installing a clean pad filter.
  • 185—Replace dehumidifier filter. Clear the monitor by tapping “dismiss” after putting in a fresh filter.
  • 187—Clean or install a new ventilator filter. Clear the thermostat by touching “dismiss” after adding a new filter.
  • 188/189—Install a new UV bulb. Call Bryant Heating & Cooling Service Experts at 226-773-3357 for assistance.
  • 210—Register online for outdoor temperature. Download the Lyric app to finish this step and ensure accurate thermostat operation.
  • 388—Register online for remote access and outside temperature. Get the Lyric app to complete 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. Get the Lyric app and follow the process 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. Contact Bryant Heating & Cooling Service Experts at 226-773-3357 for support.
  • 168—Wi-Fi radio error. Reach Bryant Heating & Cooling Service Experts at 226-773-3357 for help.
  • 170—Internal memory error. Call Bryant Heating & Cooling Service Experts at 226-773-3357 for assistance.
  • 171—Set date and time. Complete these settings so scheduling can run.
  • 173—Thermostat temperature sensor error. Contact Bryant Heating & Cooling Service Experts at 226-773-3357 for help.
  • 175—AC power reconnected. No action necessary.
  • 177—Indoor temperature sensor error. Reach Bryant Heating & Cooling Service Experts at 226-773-3357 for assistance.
  • 178—Outdoor temperature sensor error. Call Bryant Heating & Cooling Service Experts at 226-773-3357 for support.
  • 181/182—Replace air filter. Clear the monitor by hitting “dismiss” after putting in a fresh filter.
  • 183—Rinse humidifier tank and add a new water filter. Clear the screen by hitting “dismiss” after completing these procedures.
  • 184—Install a new humidifier pad. Clear the display by tapping “dismiss” after installing pad filter.
  • 185—Get a new dehumidifier filter. Clear the display by hitting “dismiss” after installing a clean filter.
  • 186—Clean ventilator core. Clear the screen by hitting “dismiss” after finishing this task.
  • 187—Clean or install a new ventilator filter. Clear the screen by hitting “dismiss” after installing a new filter.
  • 188/189—Add a new UV bulb. Get in touch with Bryant Heating & Cooling Service Experts at 226-773-3357 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 outdoor temperature. Use the Lyric app to complete 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 configured. Get the Lyric app and follow the steps to connect your thermostat.

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

Our Experts are Ready to Provide Assistance

If you’re still experiencing problems after working through the troubleshooting list, our professionals are here to help. Give us a call at 226-773-3357 and we’ll be out rapidly to determine the issue.

If you rely on an aging thermostat, right now is a fantastic time to consider a new device. Thermostat technology has gotten better over the last few years. Ask us for more information on how smart thermostats can make your home better while helping save on energy expenses year-round.

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