How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the leading thermostat manufacturers, and we proudly install them on a frequent basis in the U.S.. They’re long-lasting and trustworthy. Also, Honeywell is regularly enhancing its technology, resulting in more features for your family.

However, each thermostat can experience issues every now and then. Due to this, we’ve put together this helpful manual to go over troubleshooting. While Honeywell thermostat troubleshooting problems are rare, they do occur.

While you can typically solve most thermostat problems alone, they often need Expert assistance. Our heating and cooling professionals are ready to support you when you need us. We’re just a call away at 866-397-3787.

Let’s begin the process by determining what type of thermostat your home has.

What Model of Thermostat Do I Have?

There are three models of thermostats:

  • Manual—This is the classic dial-shaped thermostat. You won’t experience error codes with this kind, but it’s also the least efficient for lowering energy costs.
  • Programmable—This thermostat has a digital screen and arrows you use to choose your desired temperature. You can also set daily programs to decrease the temperature when you’re gone and set it higher when you get back.
  • Smart—You won’t have to schedule any programs on this thermostat, because it learns your day. It automatically changes the temperature when you or loved ones are gone to help you save on energy expenses. You can also adjust the temperature anywhere on your phone or other Wi-Fi-enabled device.

As is the case with the majority of technologically advanced things, there are common problems that can take place. The majority of of these problems don’t need pro support and are easy to repair on your own.

Common Honeywell Thermostat Troubleshooting Problems

Each Honeywell thermostat has a special set of codes matching the glitches that occur.

Think how simple it can be to restore a computer by restarting it. In many instances, diagnosing a thermostat can be just as easy.

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

Display is Blank

If the display is blank on your programmable thermostat, you could need to put in new batteries. If that doesn’t take care of the malfunction or you use a smart thermostat, there could be a wiring problem.

Next, you should check the power is flowing for your furnace or air handler. Make sure the switch close to the indoor system is switched “on”.

In addition to that, you should confirm all furnace cabinet or air handler doors/panels are tightly fastened.

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

Infrequently, a clear display might indicate you should get a new thermostat.

HVAC Unit Won’t Run

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

When it’s hot, make sure you put the thermostat below the room temperature. In the winter, make sure it’s higher. This sounds silly, but we’ve seen it occur a lot of times.

Make sure the power switch near your indoor equipment is in the “on” position. You should also make sure the cabinet doors or panels are closed on your furnace cabinet or air handler. An open panel can trigger the safety switch, cutting off electricity to the equipment.

Equipment still won’t run? Confirm circuit breakers haven’t tripped and that your HVAC system isn’t showing error codes.

“Cool On” or “Heat On” is Flickering

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

Then, check it’s telling the correct equipment to start. This is usually shown by “cool on,” “heat on” or a picture.

If these words or the icon is flashing, your thermostat is in a five-minute delay state. This feature stops your unit 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 needs service. Call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for support.
  • 168—Wi-Fi radio error. Contact Lyric technical support at 800-633-3991. 170—Internal memory error. Contact Lyric technical support at 800-633-3991.
  • 171—Set date and time. Finish these settings so scheduling can take place.
  • 173—Thermostat temperature sensor error. Reach Lyric technical support at 800-633-3991.
  • 175—AC power restarted. No action necessary.
  • 181/182—Install a new air filter. Clear the monitor by tapping “dismiss” after putting in a new filter.
  • 184—Install a new humidifier pad. Clear the thermostat by touching “dismiss” after putting in a clean pad filter.
  • 185—Install a new dehumidifier filter. Clear the display by hitting “dismiss” after adding a fresh filter.
  • 187—Clean or replace ventilator filter. Clear the screen by hitting “dismiss” after putting in a new filter.
  • 188/189—Replace UV bulb. Contact Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for help.
  • 210—Register online for outside temperature. Use the Lyric app to complete this step and ensure proper thermostat operation.
  • 388—Register online for remote access and outside temperature. Get the Lyric app to complete this step and ensure accurate thermostat operation.
  • 399—No Internet. Confirm 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. Use the Lyric app and follow the steps to connect your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005)

  • 164—Heat pump requires service. Reach Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for assistance.
  • 168—Wi-Fi radio error. Contact Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for assistance.
  • 170—Internal memory error. Reach Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for assistance.
  • 171—Set date and time. Finalize these settings so scheduling can run.
  • 173—Thermostat temperature sensor error. Call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for help.
  • 175—AC power restored. No action necessary.
  • 177—Indoor temperature sensor error. Call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for help.
  • 178—Outdoor temperature sensor error. Reach Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for help.
  • 181/182—Replace air filter. Clear the thermostat by tapping “dismiss” after adding a new filter.
  • 183—Rinse humidifier tank and install a new water filter. Clear the thermostat by tapping “dismiss” after finishing these tasks.
  • 184—Replace humidifier pad. Clear the display by touching “dismiss” after installing pad filter.
  • 185—Replace dehumidifier filter. Clear the thermostat by touching “dismiss” after adding a new filter.
  • 186—Rinse ventilator core. Clear the screen by touching “dismiss” after completing this task.
  • 187—Clean or replace ventilator filter. Clear the screen by tapping “dismiss” after installing a new filter.
  • 188/189—Get a new UV bulb. Reach Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for support.
  • 210—Register online for outside temperature. Get the Lyric app to finish this step and ensure proper thermostat operation.
  • 388—Register online for remote access and outdoor temperature. Get the Lyric app to complete this step and ensure correct 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. Get the Lyric app and follow the procedures to connect your thermostat.

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

Our Experts are Ready to Provide Assistance

If you’re still experiencing problems after working through the troubleshooting list, our professionals are here to support you. Reach us at 866-397-3787 and we’ll arrive as fast as we can to diagnose the issue.

If you rely on a dated thermostat, now is a fantastic time to think over a new device. Thermostat technology has gotten better lately Ask us for more information on how smart thermostats can make your residence comfier while helping save on energy expenses year-round.