How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the leading thermostat producers, and we proudly install them on a frequent basis in Buffalo. They’re durable and trustworthy. In addition, Honeywell is constantly updating its technology, resulting in more features for your residence.

Still, every thermostat can experience troubles occasionally. As a result, we’ve compiled this informative guide to go over troubleshooting.

While you can often repair many thermostat problems by yourself, they sometimes call for Expert assistance. Our heating and cooling Experts are ready to assist you when you need us. We’re just a call away at 716-427-6807.

Let’s get started with the process by finding out what kind of thermostat your home has.

What Kind of Thermostat Do I Have?

There are three models of thermostats:

  • Manual—This is the older dial-shaped thermostat. You won’t experience error codes with this one, but it’s also the least efficient for saving on heating and cooling bills.
  • Programmable—This thermostat includes a digital screen and arrows you press to choose your desired temperature. You can also set daily programs to lower the temperature when you’re at work and increase it when you get back.
  • Smart—You won’t have to make any programs on this thermostat, as it adjusts to your day. It instinctively adjusts the temperature when you or family members are gone to help you save on utility expenses. You can also adjust the temperature anywhere via your phone or other Wi-Fi-enabled device. 

As is the case with many technologically advanced products, there are regular malfunctions that can occur. The majority of of these situations don’t call for Expert support and are easy to solve on your own.

Common Honeywell Thermostat Issues

Each thermostat has a special set of codes assigned to the troubles that occur.

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

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

Display is Blank

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

Next, you should make sure the power is on 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 tightly in place.

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

While it’s less common, a clear display can mean you should replace your thermostat.

Comfort Unit Won’t Start

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

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

Ensure the power switch by your indoor system is in the “on” position. You should also check the cabinet doors or panels are secure on your furnace cabinet or air handler. An open panel can trip the safety switch, diverting power to the equipment.

Equipment still won’t run? Confirm circuit breakers haven’t turned off and that your HVAC unit isn’t displaying error codes.

“Cool On” or “Heat On” is Flashing

First, verify your thermostat is set to “cool” or “heat.”

Then, make sure it’s telling the right unit to turn on. This is usually indicated by “cool on,” “heat on” or an illustration.

If this phrase or the illustration is flashing, your thermostat is in a five-minute delay status. This setting keeps your unit from harmful short cycling. This could occur if you lose power.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump requires service. Call Sunbeam Service Experts at 716-427-6807 for help.
  • 168—Wi-Fi radio error. Contact 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 take place.
  • 173—Thermostat temperature sensor error. Reach Lyric technical support at 800-633-3991.
  • 175—AC power restored. No action needed.
  • 181/182—Put in a new air filter. Clear the thermostat by touching “dismiss” after installing a new filter.
  • 184—Install a new humidifier pad. Clear the display by tapping “dismiss” after adding a new pad filter.
  • 185—Put in a new dehumidifier filter. Clear the screen by hitting “dismiss” after adding a fresh filter.
  • 187—Clean or put in a new ventilator filter. Clear the screen by touching “dismiss” after installing a new filter.
  • 188/189—Install a new UV bulb. Call Sunbeam Service Experts at 716-427-6807 for support.
  • 210—Register online for outdoor temperature. Get 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 select new Wi-Fi network.
  • 508—Wi-Fi not set up. Download the Lyric app and follow the process to link your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump must be serviced service. Reach Sunbeam Service Experts at 716-427-6807 for help.
  • 168—Wi-Fi radio error. Call Sunbeam Service Experts at 716-427-6807 for support.
  • 170—Internal memory error. Call Sunbeam Service Experts at 716-427-6807 for help.
  • 171—Set date and time. Finish these settings so scheduling can operate.
  • 173—Thermostat temperature sensor error. Contact Sunbeam Service Experts at 716-427-6807 for help.
  • 175—AC power resumed. No action required.
  • 177—Indoor temperature sensor error. Reach Sunbeam Service Experts at 716-427-6807 for assistance.
  • 178—Outdoor temperature sensor error. Call Sunbeam Service Experts at 716-427-6807 for support.
  • 181/182—Install a new air filter. Clear the monitor by tapping “dismiss” after installing a fresh filter.
  • 183—Clean humidifier tank and add a new water filter. Clear the thermostat by tapping “dismiss” after doing these steps.
  • 184—Get a new humidifier pad. Clear the monitor by touching “dismiss” after installing pad filter.
  • 185—Get a new dehumidifier filter. Clear the screen by tapping “dismiss” after installing a new filter.
  • 186—Wash ventilator core. Clear the screen by tapping “dismiss” after completing this task.
  • 187—Wash or get a new ventilator filter. Clear the display by hitting “dismiss” after getting a new filter.
  • 188/189—Add a new UV bulb. Contact Sunbeam Service Experts at 716-427-6807 for support.
  • 210—Register online for exterior temperature. Get the Lyric app to finish this step and ensure proper thermostat operation.
  • 388—Register online for remote access and outside temperature. Use the Lyric app to do 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. Download the Lyric app and follow the process to connect your thermostat.

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

Our Experts are Here to Provide Support

If you’re still having issues after trying the troubleshooting list, our Experts are here to support you. Reach us at 716-427-6807 and we’ll come to your house rapidly to figure out the problem.

If you have an older thermostat, right now is a great time to think about a new thermostat. Thermostat technology has gotten better in recent years Ask us for more info on how smart thermostats can make your home more comfortable while helping save on utility costs throughout the year.

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