How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the leading thermostat manufacturers, and we proudly install them on a usual basis in Kitchener. They’re long-lasting and dependable. Plus, Honeywell is constantly updating its technology, resulting in more features for your home.

Nevertheless, each thermostat can have errors every now and then. That’s why we’ve compiled this helpful handbook to run through troubleshooting. While Honeywell thermostat problems are rare, they do occur. 

While you can often repair many thermostat problems alone, they occasionally need Expert help. Our HVAC professionals are ready to support you when you need us. We’re just a call away at 519-804-1617.

Let’s begin the process by determining what model of thermostat your home 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 experience error codes with this one, but it’s also the least efficient for reducing heating and cooling costs.
  • Programmable—This thermostat includes a digital screen and arrows you touch to determine your desired temperature. You can also set daily programs to reduce the temperature when you’re gone and raise it when you return.
  • Smart—You won’t have to schedule any programs on this thermostat, since it learns your day. It intuitively adjusts the temperature when you or loved ones are out and about to help you save on energy expenses. You can also change the temperature anywhere via your phone or other Wi-Fi-enabled device. 

As is the case with most technologically advanced things, there are common malfunctions that can happen. Most of these issues don’t call for professional assistance and are uncomplicated enough to solve by yourself.

Common Honeywell Thermostat Problems

Every thermostat has a special kind of codes matching the malfunctions that take place.

Think how simple it can be to fix a computer by restarting it. For the most part, correcting a thermostat can be just as uncomplicated.

Here are some of the most common Honeywell thermostat issues. These include the following programmable thermostats:

Display is Blank

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

Next, you should ensure the power is flowing for your furnace or air handler. Make sure the switch near the indoor system is in the “on” position.

In addition to that, you should make certain all furnace cabinet or air handler doors/panels are securely fastened.

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

While it’s less common, a blank screen might indicate you need to install a new thermostat.

Comfort System Won’t Run

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

During warm weather, confirm you schedule the thermostat below the ambient temperature. When it’s cold, confirm it’s higher. This sounds absurd, but we’ve seen it happen many times.

Ensure the power switch close to your indoor system is in the “on” position. You should also make sure the cabinet doors or panels are secure on your furnace cabinet or air handler. An unsecured panel can trip the safety switch, cutting off current to the system.

Heating or cooling still won’t turn on? Verify circuit breakers haven’t turned off and that your HVAC equipment isn’t displaying error codes.

“Cool On” or “Heat On” is Blinking

To begin, confirm your thermostat is on “cool” or “heat.”

Then, make sure it’s calling for the correct system to turn on. This is usually shown 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 equipment from damaging short cycling. This may take place if you lose power.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump needs service. Call Boehmers/Cronin Emery Service Experts at 519-804-1617 for assistance.
  • 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. Finalize these settings so scheduling can run.
  • 173—Thermostat temperature sensor error. Contact Lyric technical support at 800-633-3991.
  • 175—AC power restored. No action necessary.
  • 181/182—Put in a new air filter. Clear the display by tapping “dismiss” after installing a fresh filter.
  • 184—Replace humidifier pad. Clear the thermostat by touching “dismiss” after putting in a fresh pad filter.
  • 185—Replace dehumidifier filter. Clear the monitor by tapping “dismiss” after putting in a clean filter.
  • 187—Rinse or replace ventilator filter. Clear the screen by tapping “dismiss” after adding a clean filter.
  • 188/189—Install a new UV bulb. Contact Boehmers/Cronin Emery Service Experts at 519-804-1617 for assistance.
  • 210—Register online for outdoor temperature. Download the Lyric app to complete this step and ensure correct thermostat operation.
  • 388—Register online for remote access and outdoor temperature. Download the Lyric app to complete 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 pick new Wi-Fi network.
  • 508—Wi-Fi not set up. Use the Lyric app and follow the process to connect your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump needs service. Call Boehmers/Cronin Emery Service Experts at 519-804-1617 for help.
  • 168—Wi-Fi radio error. Contact Boehmers/Cronin Emery Service Experts at 519-804-1617 for help.
  • 170—Internal memory error. Reach Boehmers/Cronin Emery Service Experts at 519-804-1617 for help.
  • 171—Set date and time. Finalize these settings so scheduling can operate.
  • 173—Thermostat temperature sensor error. Call Boehmers/Cronin Emery Service Experts at 519-804-1617 for support.
  • 175—AC power restored. No action needed.
  • 177—Indoor temperature sensor error. Contact Boehmers/Cronin Emery Service Experts at 519-804-1617 for support.
  • 178—Outdoor temperature sensor error. Call Boehmers/Cronin Emery Service Experts at 519-804-1617 for help.
  • 181/182—Get a new air filter. Clear the display by tapping “dismiss” after putting in a clean filter.
  • 183—Rinse humidifier tank and replace water filter. Clear the screen by hitting “dismiss” after doing these procedures.
  • 184—Install a new humidifier pad. Clear the thermostat by touching “dismiss” after adding a new pad filter.
  • 185—Install a new dehumidifier filter. Clear the display by hitting “dismiss” after putting in a clean filter.
  • 186—Rinse ventilator core. Clear the display by tapping “dismiss” after completing this task.
  • 187—Rinse or replace ventilator filter. Clear the monitor by hitting “dismiss” after getting a new filter.
  • 188/189—Add a new UV bulb. Reach Boehmers/Cronin Emery Service Experts at 519-804-1617 for assistance.
  • 210—Register online for outside temperature. Download the Lyric app to complete this step and ensure correct thermostat operation.
  • 388—Register online for remote access and outdoor temperature. Get 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 choose new Wi-Fi network.
  • 508—Wi-Fi not configured. Download the Lyric app and follow the procedures to connect your thermostat.

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

Our Experts are Here to Provide Support

If you’re still running into troubles after going through the troubleshooting list, our Experts are ready to assist you. Reach us at 519-804-1617 and we’ll arrive rapidly to diagnose the problem.

If you rely on a dated thermostat, now is a good time to think over a new device. Thermostat technology has gotten better in recent years Ask us for more info on how smart thermostats can make your house comfier while helping save on energy bills year-round.

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