How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the best thermostat manufacturers, and we proudly install them on a usual basis in Elkhart. They’re long-lasting and trustworthy. Also, Honeywell is regularly improving its technology, bringing more features for your house.

Still, each thermostat can experience issues occasionally. That’s why we’ve compiled this helpful manual to run through troubleshooting.

While you can usually repair many thermostat troubles by yourself, they sometimes need Expert help. Our heating and cooling pros are available to help when you need us. We’re just a call away at 574-218-6404.

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

What Type 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 reducing heating and cooling bills.
  • Programmable—This thermostat features a digital screen and arrows you touch to choose your desired temperature. You can also set daily programs to reduce the temperature when you’re at work and set it higher when you return.
  • Smart—You won’t have to set any programs on this thermostat, since it adjusts to your schedule. It instinctively raises and lowers the temperature when you or loved ones are away to help you save on energy costs. You can also adjust the temperature anywhere via your phone or other Wi-Fi-enabled device. 

As you know the majority of technologically advanced solutions, there are several problems that can take place. The majority of of these issues don’t require Expert help and are easy to solve on your own.

Common Honeywell Thermostat Issues

All thermostats have a special group of codes assigned to the troubles that take place.

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

Here is a listing the most common Honeywell thermostat errors. These are applicable to the following programmable thermostats:

Display is Blank

If the screen is empty on your programmable thermostat, you may need to replace the batteries. If that doesn’t take care of the issue or you rely on a smart thermostat, there could be a wiring issue.

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

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

A panel that isn’t tight may activate the safety switch, which stops power to the equipment.

Infrequently, a clear screen could signify you need to install a new thermostat.

HVAC Equipment Won’t Run

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

During warm weather, confirm you set the thermostat lower than the ambient temperature. When it’s cold, confirm it’s higher. This sounds goofy, but we’ve seen it take place lots of times.

Confirm the power switch close to your indoor unit is in the “on” position. You should also comfirm the cabinet doors or panels are tight on your furnace cabinet or air handler. An open panel can activate the safety switch, stopping power to the unit.

Equipment still won’t start? Confirm circuit breakers haven’t tripped and that your HVAC unit isn’t experiencing error codes.

“Cool On” or “Heat On” is Flashing

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

Then, verify it’s signaling the right unit to start. This is typically indicated by “cool on,” “heat on” or a picture.

If these words or the picture is flashing, your thermostat is in a five-minute delay mode. This setting keeps your unit 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 BW/Cook Service Experts at 574-218-6404 for support.
  • 168—Wi-Fi radio error. Contact Lyric technical support at 800-633-3991. 170—Internal memory error. Reach Lyric technical support at 800-633-3991.
  • 171—Set date and time. Complete these settings so scheduling can occur.
  • 173—Thermostat temperature sensor error. Call Lyric technical support at 800-633-3991.
  • 175—AC power restarted. No action required.
  • 181/182—Install a new air filter. Clear the display by touching “dismiss” after putting in a fresh filter.
  • 184—Replace humidifier pad. Clear the monitor by tapping “dismiss” after putting in a clean pad filter.
  • 185—Replace dehumidifier filter. Clear the display by hitting “dismiss” after installing a fresh filter.
  • 187—Rinse or install a new ventilator filter. Clear the monitor by tapping “dismiss” after installing a new filter.
  • 188/189—Get a new UV bulb. Call BW/Cook Service Experts at 574-218-6404 for help.
  • 210—Register online for outside temperature. Use the Lyric app to do this step and ensure correct thermostat operation.
  • 388—Register online for remote access and exterior 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. Download the Lyric app and follow the procedure to configure your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump requires service. Reach BW/Cook Service Experts at 574-218-6404 for assistance.
  • 168—Wi-Fi radio error. Contact BW/Cook Service Experts at 574-218-6404 for assistance.
  • 170—Internal memory error. Contact BW/Cook Service Experts at 574-218-6404 for support.
  • 171—Set date and time. Finish these settings so scheduling can run.
  • 173—Thermostat temperature sensor error. Reach BW/Cook Service Experts at 574-218-6404 for support.
  • 175—AC power reconnected. No action needed.
  • 177—Indoor temperature sensor error. Call BW/Cook Service Experts at 574-218-6404 for help.
  • 178—Outdoor temperature sensor error. Call BW/Cook Service Experts at 574-218-6404 for support.
  • 181/182—Replace air filter. Clear the display by tapping “dismiss” after putting in a new filter.
  • 183—Wash humidifier tank and add a new water filter. Clear the monitor 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 tapping “dismiss” after adding a new filter.
  • 186—Wash ventilator core. Clear the display by touching “dismiss” after doing this task.
  • 187—Clean or get a new ventilator filter. Clear the display by tapping “dismiss” after installing a new filter.
  • 188/189—Get a new UV bulb. Reach BW/Cook Service Experts at 574-218-6404 for help.
  • 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. Download the Lyric app to complete 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 select new Wi-Fi network.
  • 508—Wi-Fi not configured. Use the Lyric app and follow the process to connect your thermostat.

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

Our Experts are Available to Help

If you’re still experiencing troubles after trying the troubleshooting steps, our professionals are available to support you. Reach us at 574-218-6404 and we’ll arrive quickly to figure out the issue.

If you use an older thermostat, today is a great time to think about a replacement. Thermostat technology has come a long way lately Ask us for more info on how smart thermostats can make your house more comfortable while helping save on heating and cooling costs all year.

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