How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the best thermostat brands, and we proudly install them on a usual basis in Kansas City. They’re durable and trustworthy. In addition, Honeywell is constantly improving its technology, offering more features for your household.

However, every thermostat can experience issues every so often. Due to this, we’ve prepared this informative guidebook to run through troubleshooting.

While you can typically repair the majority of thermostat issues on your own, they sometimes call for Expert help. Our home comfort pros are here to help when you need us. We’re just a call away at 816-787-0500.

Let’s get started with the process by figuring out what type of thermostat your residence 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 have error codes with this type, but it’s also the least efficient for lowering heating and cooling bills.
  • Programmable—This thermostat features a digital screen and arrows you use to determine your desired temperature. You can also set daily programs to decrease the temperature when you’re gone and set it higher when you come home.
  • Smart—You won’t have to set any programs on this thermostat, since it adjusts to your schedule. It intuitively changes the temperature when you or other household members are gone to help you save on heating and cooling costs. You can also raise or lower the temperature anywhere on your phone or other Wi-Fi-enabled device. 

As you’re aware many technologically advanced products, there are several malfunctions that might take place. The majority of of these troubles don’t require pro help and are easy to fix alone.

Common Honeywell Thermostat Troubles

Every thermostat has an exclusive set of codes matching the malfunctions that occur.

Think how uncomplicated 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 reported Honeywell thermostat issues. These include the following programmable thermostats:

Display is Blank

If the display is clear on your programmable thermostat, you might need to replace the batteries. If that doesn’t solve the malfunction or you rely on a smart thermostat, there may be a wiring issue.

Next, you should check the power is flowing for your furnace or air handler. Verify the switch close to the indoor unit is switched “up”.

Also, 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 equipment.

Less frequently, a clear screen may mean you need to get a new thermostat.

Heating and Cooling System Won’t Start

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

In the summer, verify you schedule the thermostat lower than the room temperature. When it’s cool, confirm it’s higher. This sounds goofy, but we’ve seen it happen many times.

Make sure the power switch near your indoor system is in the “on” position. You should also comfirm the cabinet doors or panels are closed on your furnace cabinet or air handler. A loose panel can trip the safety switch, stopping current to the unit.

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

“Cool On” or “Heat On” is Blinking

To begin, make sure your thermostat is on “cool” or “heat.”

Then, make sure it’s signaling the right unit to start. This is usually indicated by “cool on,” “heat on” or an icon.

If these words or the illustration is blinking, your thermostat is in a five-minute delay mode. This setting keeps your equipment from damaging short cycling. This could take place if your power is interrupted.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump must be serviced. Call Neal Harris Service Experts at 816-787-0500 for help.
  • 168—Wi-Fi radio error. Reach 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 run.
  • 173—Thermostat temperature sensor error. Call Lyric technical support at 800-633-3991.
  • 175—AC power restarted. No action needed.
  • 181/182—Put in a new air filter. Clear the monitor by touching “dismiss” after adding a fresh filter.
  • 184—Put in a new humidifier pad. Clear the monitor by tapping “dismiss” after putting in a clean pad filter.
  • 185—Install a new dehumidifier filter. Clear the screen by tapping “dismiss” after adding a clean filter.
  • 187—Rinse or replace ventilator filter. Clear the monitor by tapping “dismiss” after installing a fresh filter.
  • 188/189—Get a new UV bulb. Contact Neal Harris Service Experts at 816-787-0500 for help.
  • 210—Register online for outside temperature. Download the Lyric app to do this step and ensure correct thermostat operation.
  • 388—Register online for remote access and outdoor temperature. Download the Lyric app to do this step and ensure accurate 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. Get the Lyric app and follow the procedure to link your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump must be serviced service. Call Neal Harris Service Experts at 816-787-0500 for support.
  • 168—Wi-Fi radio error. Reach Neal Harris Service Experts at 816-787-0500 for help.
  • 170—Internal memory error. Contact Neal Harris Service Experts at 816-787-0500 for support.
  • 171—Set date and time. Finish these settings so scheduling can work.
  • 173—Thermostat temperature sensor error. Call Neal Harris Service Experts at 816-787-0500 for assistance.
  • 175—AC power restored. No action needed.
  • 177—Indoor temperature sensor error. Call Neal Harris Service Experts at 816-787-0500 for support.
  • 178—Outdoor temperature sensor error. Contact Neal Harris Service Experts at 816-787-0500 for support.
  • 181/182—Install a new air filter. Clear the monitor by touching “dismiss” after installing a fresh filter.
  • 183—Wash humidifier tank and add a new water filter. Clear the screen by touching “dismiss” after doing these tasks.
  • 184—Install a new humidifier pad. Clear the display by touching “dismiss” after getting a new pad filter.
  • 185—Get a new dehumidifier filter. Clear the monitor by touching “dismiss” after adding a fresh filter.
  • 186—Rinse ventilator core. Clear the screen by tapping “dismiss” after completing this task.
  • 187—Clean or replace ventilator filter. Clear the monitor by tapping “dismiss” after buying a new filter.
  • 188/189—Get a new UV bulb. Get in touch with Neal Harris Service Experts at 816-787-0500 for support.
  • 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 outside temperature. Use the Lyric app to finish this step and ensure accurate thermostat operation.
  • 399—No Internet. Verify 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. Use the Lyric app and follow the process to connect your thermostat.

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

Our Experts are Available to Provide Assistance

If you’re still running into problems after working through the troubleshooting steps, our pros are here to assist you. Give us a call at 816-787-0500 and we’ll come to your house as fast as we can to figure out the malfunction.

If you rely on an older thermostat, today is a fantastic time to think over a replacement. Thermostat technology has advanced over the last few years. Ask us for more information on how smart thermostats can make your residence better while helping save on heating and cooling bills throughout the year.

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