How to Troubleshoot Honeywell Thermostat Errors

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

However, each thermostat can experience problems every so often. That’s why we’ve put together this valuable guide to run through troubleshooting.

While you can typically repair most thermostat troubles by yourself, they often require Expert support. Our home comfort Experts are available to support 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 kinds 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 reducing energy bills.
  • Programmable—This thermostat has a digital screen and arrows you use 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, as it picks up on your day. 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 using your phone or other Wi-Fi-enabled device. 

As you know the majority of technologically advanced solutions, there are several problems that may happen. Most of these situations don’t call for pro support and are easy to solve alone.

Common Honeywell Thermostat Problems

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

Think how simple 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 issues. These are applicable to the following programmable thermostats:

Display is Blank

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

Next, you should check 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 secured.

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

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

Heating and Cooling Equipment Won’t Turn On

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

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

Ensure the power switch by your indoor unit is in the “on” position. You should also comfirm the cabinet doors or panels are tight on your furnace cabinet or air handler. An unsecured panel can trigger the safety switch, cutting off power to the equipment.

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

Then, ensure it’s telling the correct system to start. 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 stops your unit from harmful short cycling. This can occur if your power is interrupted.

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 help.
  • 168—Wi-Fi radio error. Reach 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 hitting “dismiss” after installing a clean pad filter.
  • 185—Replace dehumidifier filter. Clear the screen by tapping “dismiss” after putting in a clean filter.
  • 187—Clean or install a new ventilator filter. Clear the thermostat by touching “dismiss” after putting in a new filter.
  • 188/189—Install a new UV bulb. Ring 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 correct thermostat operation.
  • 388—Register online for remote access and outside 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 pick new Wi-Fi network.
  • 508—Wi-Fi not set up. Get the Lyric app and follow the process to link your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump requires service. Reach 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 support.
  • 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 screen by tapping “dismiss” after adding a fresh filter.
  • 183—Rinse humidifier tank and add a new water filter. Clear the monitor by hitting “dismiss” after completing these steps.
  • 184—Install a new humidifier pad. Clear the screen by hitting “dismiss” after installing pad filter.
  • 185—Install 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 completing this task.
  • 187—Clean or get a new ventilator filter. Clear the screen by tapping “dismiss” after installing a new filter.
  • 188/189—Add a new UV bulb. Reach Bryant Heating & Cooling Service Experts at 226-773-3357 for help.
  • 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 outdoor temperature. Get 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 pick 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 Available to Provide Support

If you’re still running into problems after working through the troubleshooting list, our Experts are here to help. Give us a call at 226-773-3357 and we’ll be out as fast as we can to determine the malfunction.

If you use a dated thermostat, today 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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