How to Troubleshoot Honeywell Thermostat Errors

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

Nevertheless, every thermostat can have issues every now and then. That’s why we’ve put together this helpful manual to go over troubleshooting.

While you can often solve most thermostat problems on your own, they occasionally require Expert support. Our HVAC professionals are ready to help when you need us. We’re merely a call away at 352-414-4006.

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

What Model of Thermostat Do I Have?

There are three models of thermostats:

  • Manual—This is the older dial-shaped thermostat. You won’t run into error codes with this type, but it’s also the least efficient for reducing utility bills.
  • Programmable—This thermostat includes a digital screen and arrows you touch to determine your desired temperature. You can also use daily programs to lower the temperature when you’re at work and raise it when you return.
  • Smart—You won’t have to make any programs on this thermostat, because it picks up on your schedule. It automatically adjusts the temperature when you or loved ones are away to help you save on utility expenses. You can also adjust the temperature anywhere using your phone or other Wi-Fi-enabled device. 

As is the case with the majority of technologically advanced solutions, there are common problems that can take place. Many of these problems don’t require pro assistance and are uncomplicated enough to repair alone.

Common Honeywell Thermostat Issues

Each thermostat has a special group of codes assigned to the issues that happen.

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

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

Display is Blank

If the screen is clear on your programmable thermostat, you may need to replace the batteries. If that doesn’t take care of the malfunction or you have a smart thermostat, there might be a wiring problem.

Next, you should make sure the power is enabled for your furnace or air handler. Make sure the switch near the indoor unit is switched “on”.

Additionally, you should make certain all furnace cabinet or air handler doors/panels are tightly secured.

A loose panel may trip the safety switch, which disconnects power to the unit.

Infrequently, an empty monitor might signify you need to install a new thermostat.

Comfort System Won’t Start

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

During warm weather, make sure you set the thermostat lower than the current temperature. When it’s cold, make sure it’s higher. This sounds absurd, but we’ve seen it take place a lot of times.

Confirm the power switch by your indoor system 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, diverting power to the system.

Heating or cooling still won’t turn on? Confirm circuit breakers haven’t tripped and that your HVAC equipment isn’t showing error codes.

“Cool On” or “Heat On” is Blinking

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

Then, ensure it’s signaling the right equipment to turn on. This is typically shown by “cool on,” “heat on” or a picture.

If this set of words or the illustration is blinking, your thermostat is in a five-minute delay mode. This setting stops your unit from bad 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 Service Experts Heating & Air Conditioning at 352-414-4006 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. Complete these settings so scheduling can occur.
  • 173—Thermostat temperature sensor error. Reach Lyric technical support at 800-633-3991.
  • 175—AC power restarted. No action required.
  • 181/182—Install a new air filter. Clear the thermostat by tapping “dismiss” after putting in a new filter.
  • 184—Put in a new humidifier pad. Clear the display by hitting “dismiss” after installing a new pad filter.
  • 185—Put in a new dehumidifier filter. Clear the display by tapping “dismiss” after installing a clean filter.
  • 187—Wash or put in a new ventilator filter. Clear the screen by hitting “dismiss” after installing a new filter.
  • 188/189—Replace UV bulb. Contact Service Experts Heating & Air Conditioning at 352-414-4006 for help.
  • 210—Register online for outside temperature. Get the Lyric app to do this step and ensure accurate thermostat operation.
  • 388—Register online for remote access and outside temperature. Use the Lyric app to finish 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 set up. Get the Lyric app and follow the process to connect your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump needs service. Contact Service Experts Heating & Air Conditioning at 352-414-4006 for help.
  • 168—Wi-Fi radio error. Reach Service Experts Heating & Air Conditioning at 352-414-4006 for help.
  • 170—Internal memory error. Contact Service Experts Heating & Air Conditioning at 352-414-4006 for help.
  • 171—Set date and time. Finalize these settings so scheduling can work.
  • 173—Thermostat temperature sensor error. Reach Service Experts Heating & Air Conditioning at 352-414-4006 for help.
  • 175—AC power resumed. No action needed.
  • 177—Indoor temperature sensor error. Contact Service Experts Heating & Air Conditioning at 352-414-4006 for support.
  • 178—Outdoor temperature sensor error. Reach Service Experts Heating & Air Conditioning at 352-414-4006 for support.
  • 181/182—Get a new air filter. Clear the display by tapping “dismiss” after installing a clean filter.
  • 183—Rinse humidifier tank and replace water filter. Clear the display by touching “dismiss” after completing these procedures.
  • 184—Install a new humidifier pad. Clear the screen by tapping “dismiss” after getting a new pad filter.
  • 185—Get a new dehumidifier filter. Clear the monitor by hitting “dismiss” after putting in a clean filter.
  • 186—Wash ventilator core. Clear the monitor by hitting “dismiss” after finishing this task.
  • 187—Clean or get a new ventilator filter. Clear the screen by hitting “dismiss” after installing a new filter.
  • 188/189—Add a new UV bulb. Reach Service Experts Heating & Air Conditioning at 352-414-4006 for help.
  • 210—Register online for outside temperature. Use the Lyric app to complete this step and ensure accurate thermostat operation.
  • 388—Register online for remote access and outside temperature. Use the Lyric app to complete this step and ensure proper 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 connected. Use the Lyric app and follow the steps 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 having problems after trying the troubleshooting list, our professionals are here to help. Give us a call at 352-414-4006 and we’ll come to your house as fast as we can to determine the malfunction.

If you use an older thermostat, right now is a good time to consider a replacement. Thermostat technology has advanced over the last few years. Ask us for more information on how smart thermostats can make your home more comfortable while helping save on heating and cooling bills year-round.

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