How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the leading thermostat manufacturers, and we proudly install them on a regular basis in Pierre. They’re durable and reliable. In addition, Honeywell is constantly advancing its technology, resulting in more features for your home.

However, every thermostat can have problems from time to time. As a result, we’ve compiled this valuable guidebook to run through troubleshooting.

While you can usually solve many thermostat troubles on your own, they occasionally call for Expert help. Our heating and cooling professionals are ready to assist you when you need us. We’re just a call away at 605-223-0307.

Let’s begin the process by figuring out what kind of thermostat your residence has.

What Model of Thermostat Do I Have?

There are three types of thermostats:

  • Manual—This is the classic dial-shaped thermostat. You won’t have error codes with this type, but it’s also the least efficient for saving on heating and cooling costs.
  • Programmable—This thermostat includes a digital screen and arrows you touch to set your desired temperature. You can also use daily programs to decrease the temperature when you’re at work and set it higher when you return.
  • Smart—You won’t have to make any programs on this thermostat, since it adjusts to your day. It instinctively raises and lowers the temperature when you or loved ones are out and about to help you save on utility bills. You can also adjust the temperature anywhere using your phone or other Wi-Fi-enabled device. 

As you know most technologically advanced solutions, there are several glitches that can take place. Most of these problems don’t require pro help and are easy to repair on your own.

Common Honeywell Thermostat Troubles

Every thermostat has a special set of codes assigned to the malfunctions that occur.

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

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

Display is Blank

If the display is blank on your programmable thermostat, you might need to put in new batteries. If that doesn’t solve the trouble or you rely on a smart thermostat, there might be a wiring problem.

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

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

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

While it’s less common, a blank display might indicate you will need to get a new thermostat.

Heating and Cooling System Won’t Run

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

In the summer, confirm you put the thermostat below the room temperature. When it’s cold, verify it’s higher. This sounds absurd, but we’ve seen it occur lots of times.

Make sure the power switch close to your indoor unit is in the “on” position. You should also check the cabinet doors or panels are secure on your furnace cabinet or air handler. An unsecured panel can trip the safety switch, stopping power to the system.

Heating or cooling still won’t turn on? Make sure circuit breakers haven’t turned off and that your HVAC system isn’t experiencing error codes.

“Cool On” or “Heat On” is Blinking

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

Then, verify it’s signaling the appropriate equipment to run. This is typically indicated by “cool on,” “heat on” or an icon.

If these words or the icon is blinking, your thermostat is in a five-minute delay status. This feature stops your system from damaging short cycling. This can take place if you lose power.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump requires service. Call Peitz Service Experts at 605-223-0307 for assistance.
  • 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. Finalize these settings so scheduling can occur.
  • 173—Thermostat temperature sensor error. Call Lyric technical support at 800-633-3991.
  • 175—AC power restarted. No action necessary.
  • 181/182—Replace air filter. Clear the screen by touching “dismiss” after adding a fresh filter.
  • 184—Install a new humidifier pad. Clear the monitor by touching “dismiss” after installing a new pad filter.
  • 185—Replace dehumidifier filter. Clear the display by hitting “dismiss” after adding a fresh filter.
  • 187—Rinse or put in a new ventilator filter. Clear the thermostat by touching “dismiss” after installing a fresh filter.
  • 188/189—Replace UV bulb. Call Peitz Service Experts at 605-223-0307 for assistance.
  • 210—Register online for outdoor temperature. Get the Lyric app to do this step and ensure proper thermostat operation.
  • 388—Register online for remote access and outside temperature. Get the Lyric app to do 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 select new Wi-Fi network.
  • 508—Wi-Fi not configured. Download the Lyric app and follow the procedure to connect your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump must be serviced service. Call Peitz Service Experts at 605-223-0307 for assistance.
  • 168—Wi-Fi radio error. Call Peitz Service Experts at 605-223-0307 for assistance.
  • 170—Internal memory error. Reach Peitz Service Experts at 605-223-0307 for assistance.
  • 171—Set date and time. Complete these settings so scheduling can work.
  • 173—Thermostat temperature sensor error. Call Peitz Service Experts at 605-223-0307 for assistance.
  • 175—AC power restored. No action required.
  • 177—Indoor temperature sensor error. Contact Peitz Service Experts at 605-223-0307 for assistance.
  • 178—Outdoor temperature sensor error. Contact Peitz Service Experts at 605-223-0307 for assistance.
  • 181/182—Get a new air filter. Clear the screen by touching “dismiss” after installing a clean filter.
  • 183—Rinse humidifier tank and replace water filter. Clear the thermostat by tapping “dismiss” after completing these steps.
  • 184—Install a new humidifier pad. Clear the monitor by tapping “dismiss” after installing pad filter.
  • 185—Replace dehumidifier filter. Clear the monitor by touching “dismiss” after putting in a clean 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 screen by hitting “dismiss” after getting a new filter.
  • 188/189—Install a new UV bulb. Contact Peitz Service Experts at 605-223-0307 for assistance.
  • 210—Register online for exterior temperature. Use the Lyric app to complete this step and ensure proper thermostat operation.
  • 388—Register online for remote access and exterior temperature. Download the Lyric app to finish 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 connected. Use the Lyric app and follow the process to connect your thermostat.

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

Our Experts are Ready to Provide Assistance

If you’re still experiencing problems after going through the troubleshooting list, our pros are here to assist you. Call us at 605-223-0307 and we’ll come to your house as fast as we can to figure out the problem.

If you use an older thermostat, right now is a good time to consider a new thermostat. Thermostat technology has gotten better over the last few years. Ask us for more information on how smart thermostats can make your residence comfier while helping save on utility bills all year.

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