How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the leading thermostat producers, and we proudly install them on a regular basis in Oklahoma City. They’re durable and dependable. Also, Honeywell is constantly improving its technology, offering more features for your family.

Still, every thermostat can run into issues from time to time. As a result, we’ve compiled this useful guidebook to go over troubleshooting.

While you can often fix the majority of thermostat problems alone, they often require Expert support. Our home comfort professionals are here to assist you when you need us. We’re only a call away at 405-432-2197.

Let’s begin the process by finding 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 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 press to set your desired temperature. You can also use daily programs to lower the temperature when you’re gone and raise it when you return.
  • Smart—You won’t have to set any programs on this thermostat, as it learns your routine. It intuitively raises and lowers the temperature when you or family members are away to help you save on energy costs. You can also change the temperature anywhere via your phone or other Wi-Fi-enabled device. 

As is the case with most technologically advanced solutions, there are several problems that might happen. The majority of of these problems don’t need professional assistance and are easy to repair on your own.

Common Honeywell Thermostat Troubles

Every thermostat has a special set of codes matching the troubles that occur.

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

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

Display is Blank

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

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

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

An unsecured panel may trigger the safety switch, which cuts off power to the system.

While it’s less common, a clear screen might signify you will need to install a new thermostat.

Heating and Cooling Equipment Won’t Turn On

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

In the summer, confirm you set the thermostat lower than the ambient temperature. When it’s cool, verify it’s higher. This sounds absurd, but we’ve seen it occur a lot of times.

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

Heating or cooling still won’t start? Confirm circuit breakers haven’t flipped and that your HVAC system isn’t showing error codes.

“Cool On” or “Heat On” is Flashing

To start, confirm your thermostat is set to “cool” or “heat.”

Then, check it’s telling the appropriate equipment to run. This is usually indicated by “cool on,” “heat on” or an icon.

If this set of words or the picture is pulsing, your thermostat is in a five-minute delay state. This mode stops your system from damaging short cycling. This may happen if you lose electricity.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump requires service. Call Gordon's Service Experts at 405-432-2197 for support.
  • 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. Complete these settings so scheduling can take place.
  • 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 thermostat by touching “dismiss” after adding a clean filter.
  • 184—Install a new humidifier pad. Clear the monitor by hitting “dismiss” after putting in a clean pad filter.
  • 185—Replace dehumidifier filter. Clear the display by hitting “dismiss” after installing a fresh filter.
  • 187—Wash or install a new ventilator filter. Clear the display by touching “dismiss” after putting in a clean filter.
  • 188/189—Replace UV bulb. Call Gordon's Service Experts at 405-432-2197 for assistance.
  • 210—Register online for outside temperature. Use the Lyric app to finish 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 choose new Wi-Fi network.
  • 508—Wi-Fi not set. Get the Lyric app and follow the process to connect your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump needs service. Call Gordon's Service Experts at 405-432-2197 for assistance.
  • 168—Wi-Fi radio error. Call Gordon's Service Experts at 405-432-2197 for help.
  • 170—Internal memory error. Call Gordon's Service Experts at 405-432-2197 for support.
  • 171—Set date and time. Complete these settings so scheduling can run.
  • 173—Thermostat temperature sensor error. Reach Gordon's Service Experts at 405-432-2197 for support.
  • 175—AC power reconnected. No action necessary.
  • 177—Indoor temperature sensor error. Call Gordon's Service Experts at 405-432-2197 for support.
  • 178—Outdoor temperature sensor error. Contact Gordon's Service Experts at 405-432-2197 for help.
  • 181/182—Replace air filter. Clear the thermostat by tapping “dismiss” after installing a new filter.
  • 183—Clean humidifier tank and replace water filter. Clear the monitor by hitting “dismiss” after completing these procedures.
  • 184—Get a new humidifier pad. Clear the display by tapping “dismiss” after getting a new pad filter.
  • 185—Get a new dehumidifier filter. Clear the thermostat by hitting “dismiss” after putting in a fresh filter.
  • 186—Rinse ventilator core. Clear the display by touching “dismiss” after completing this task.
  • 187—Wash or get a new ventilator filter. Clear the monitor by touching “dismiss” after buying a new filter.
  • 188/189—Get a new UV bulb. Contact Gordon's Service Experts at 405-432-2197 for support.
  • 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 outdoor temperature. Use the Lyric app to finish 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 up. Get the Lyric app and follow the procedures to connect your thermostat.

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

Our Experts are Here to Provide Support

If you’re still experiencing issues after trying the troubleshooting list, our Experts are ready to help. Call us at 405-432-2197 and we’ll be out rapidly to figure out the problem.

If you have a dated thermostat, today is a good time to think over 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 residence more comfortable while helping save on heating and cooling bills year-round.

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