How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the best thermostat brands, and we proudly install them on a frequent basis in Austin. They’re sturdy and dependable. In addition, Honeywell is frequently enhancing its technology, offering more features for your household.

Nevertheless, each thermostat can have issues at times. That’s why we’ve compiled this useful guidebook to walk you through troubleshooting.

While you can usually repair most thermostat issues on your own, they sometimes require Expert assistance. Our heating and cooling Experts are here to assist you when you need us. We’re only a call away at 512-596-1257.

Let’s begin the process by determining what model of thermostat your residence has.

What Model of Thermostat Do I Have?

There are three kinds of thermostats:

  • Manual—This is the older dial-shaped thermostat. You won’t have error codes with this one, but it’s also the least efficient for lowering heating and cooling costs.
  • Programmable—This thermostat has a digital screen and arrows you use to set your desired temperature. You can also set daily programs to lower the temperature when you’re gone and raise it when you come home.
  • Smart—You won’t have to set any programs on this thermostat, since it adjusts to your day. It intuitively changes the temperature when you or family members are out and about to help you save on utility costs. You can also change 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 regular problems that might happen. The majority of of these troubles don’t need Expert help and are simple to solve by yourself.

Common Honeywell Thermostat Problems

All thermostats have a special kind of codes matching the troubles that happen.

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

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

Display is Blank

If the monitor is empty on your programmable thermostat, you could need to replace the batteries. If that doesn’t solve the issue or you have a smart thermostat, there could be a wiring problem.

Next, you should make sure the power is enabled for your furnace or air handler. Confirm the switch by the indoor equipment is in the “on” position.

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

An unsecured panel may activate the safety switch, which cuts off power to the unit.

Less frequently, a clear monitor could signify you will need to replace your thermostat.

Comfort Equipment Won’t Turn On

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

During warm weather, verify you set the thermostat lower than the room temperature. When it’s cool, verify it’s higher. This sounds goofy, but we’ve seen it take place many 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. A loose panel can activate the safety switch, stopping current to the equipment.

Unit still won’t start? Make sure circuit breakers haven’t turned off and that your HVAC equipment isn’t showing error codes.

“Cool On” or “Heat On” is Blinking

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

Then, check it’s calling for the appropriate equipment to start. This is typically indicated by “cool on,” “heat on” or a picture.

If this phrase or the icon is blinking, your thermostat is in a five-minute delay status. This mode protects your equipment from harmful short cycling. This could take place if you lose power.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump must be serviced. Call Strand Brothers Service Experts at 512-596-1257 for support.
  • 168—Wi-Fi radio error. Reach 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 required.
  • 181/182—Replace air filter. Clear the monitor by touching “dismiss” after putting in a new filter.
  • 184—Install a new humidifier pad. Clear the screen by touching “dismiss” after installing a clean pad filter.
  • 185—Put in a new dehumidifier filter. Clear the display by tapping “dismiss” after putting in a clean filter.
  • 187—Wash or install a new ventilator filter. Clear the thermostat by tapping “dismiss” after adding a fresh filter.
  • 188/189—Get a new UV bulb. Contact Strand Brothers Service Experts at 512-596-1257 for assistance.
  • 210—Register online for outside temperature. Use the Lyric app to finish this step and ensure accurate thermostat operation.
  • 388—Register online for remote access and outdoor temperature. Download the Lyric app to finish 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 configured. Use the Lyric app and follow the procedure 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 Strand Brothers Service Experts at 512-596-1257 for help.
  • 168—Wi-Fi radio error. Contact Strand Brothers Service Experts at 512-596-1257 for support.
  • 170—Internal memory error. Call Strand Brothers Service Experts at 512-596-1257 for assistance.
  • 171—Set date and time. Finalize these settings so scheduling can operate.
  • 173—Thermostat temperature sensor error. Contact Strand Brothers Service Experts at 512-596-1257 for support.
  • 175—AC power reconnected. No action needed.
  • 177—Indoor temperature sensor error. Call Strand Brothers Service Experts at 512-596-1257 for help.
  • 178—Outdoor temperature sensor error. Contact Strand Brothers Service Experts at 512-596-1257 for assistance.
  • 181/182—Get a new air filter. Clear the display by touching “dismiss” after installing a new filter.
  • 183—Rinse humidifier tank and replace water filter. Clear the monitor by hitting “dismiss” after doing these procedures.
  • 184—Replace humidifier pad. Clear the monitor 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—Rinse ventilator core. Clear the display by touching “dismiss” after finishing this task.
  • 187—Rinse or install a new ventilator filter. Clear the screen by touching “dismiss” after getting a new filter.
  • 188/189—Install a new UV bulb. Contact Strand Brothers Service Experts at 512-596-1257 for help.
  • 210—Register online for outdoor temperature. Get the Lyric app to do this step and ensure accurate thermostat operation.
  • 388—Register online for remote access and outdoor temperature. Download the Lyric app to do 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 connected. Get the Lyric app and follow the steps to connect your thermostat.

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

Our Experts are Here to Help

If you’re still running into problems after trying the troubleshooting steps, our pros are here to support you. Reach us at 512-596-1257 and we’ll be out rapidly to determine the issue.

If you use a dated thermostat, today is a fantastic time to think over a replacement. Thermostat technology has gotten better lately Ask us for more info on how smart thermostats can make your home more comfortable while helping save on heating and cooling bills year-round.

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