How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the leading thermostat manufacturers, and we proudly install them on a regular basis in Houston. They’re long-lasting and dependable. Also, Honeywell is regularly improving its technology, offering more features for your household.

Still, every thermostat can experience errors now and again. That’s why we’ve prepared this useful guide to walk you through troubleshooting.

While you can usually solve many thermostat issues on your own, they often call for Expert help. Our HVAC Experts are available to assist you when you need us. We’re just a call away at 713-396-3760.

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

What Kind of Thermostat Do I Have?

There are three kinds of thermostats:

  • Manual—This is the typical dial-shaped thermostat. You won’t run into error codes with this kind, but it’s also the least efficient for lowering energy bills.
  • Programmable—This thermostat has a digital screen and arrows you press to choose your desired temperature. You can also choose daily programs to decrease the temperature when you’re away and set it higher when you come home.
  • Smart—You won’t have to schedule any programs on this thermostat, since it learns your day. It intuitively changes the temperature when you or other household members are away to help you save on heating and cooling expenses. You can also change the temperature anywhere using your phone or other Wi-Fi-enabled device. 

As you know many technologically advanced things, there are common malfunctions that might happen. Most of these problems don’t call for professional help and are uncomplicated enough to repair on your own.

Common Honeywell Thermostat Issues

All thermostats have an exclusive set of codes matching the problems that take place.

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

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

Display is Blank

If the screen is empty on your programmable thermostat, you could need to get new batteries. If that doesn’t solve the malfunction or you rely on a smart thermostat, there may be a wiring issue.

Next, you should ensure the power is enabled for your furnace or air handler. Confirm the switch near the indoor system is switched “up”.

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

An unsecured panel may trip the safety switch, which cuts off power to the system.

Less frequently, a clear display can signify you should replace your thermostat.

Comfort Equipment Won’t Start

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

When it’s hot, confirm you schedule the thermostat lower than the ambient temperature. When it’s cold, verify it’s higher. This sounds absurd, but we’ve seen it take place a lot of times.

Make sure the power switch by your indoor system is in the “on” position. You should also make sure the cabinet doors or panels are secure on your furnace cabinet or air handler. An unsecured panel can trip the safety switch, diverting power to the system.

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

“Cool On” or “Heat On” is Blinking

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

Then, make sure it’s calling for the correct system to start. This is usually indicated by “cool on,” “heat on” or an icon.

If this set of words or the picture is pulsing, your thermostat is in a five-minute delay state. This feature protects your system from harmful short cycling. This may occur if your power is interrupted.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump needs service. Call Church Services at 713-396-3760 for assistance.
  • 168—Wi-Fi radio error. Call 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 run.
  • 173—Thermostat temperature sensor error. Call Lyric technical support at 800-633-3991.
  • 175—AC power restored. No action required.
  • 181/182—Replace air filter. Clear the thermostat by touching “dismiss” after installing a fresh filter.
  • 184—Put in a new humidifier pad. Clear the thermostat by tapping “dismiss” after putting in a clean pad filter.
  • 185—Install a new dehumidifier filter. Clear the screen by touching “dismiss” after adding a fresh filter.
  • 187—Rinse or replace ventilator filter. Clear the thermostat by tapping “dismiss” after adding a fresh filter.
  • 188/189—Get a new UV bulb. Ring Church Services at 713-396-3760 for assistance.
  • 210—Register online for exterior temperature. Use the Lyric app to finish this step and ensure accurate thermostat operation.
  • 388—Register online for remote access and exterior temperature. Get 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 set. Get the Lyric app and follow the procedure to connect your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump requires service. Reach Church Services at 713-396-3760 for assistance.
  • 168—Wi-Fi radio error. Reach Church Services at 713-396-3760 for assistance.
  • 170—Internal memory error. Contact Church Services at 713-396-3760 for help.
  • 171—Set date and time. Complete these settings so scheduling can operate.
  • 173—Thermostat temperature sensor error. Call Church Services at 713-396-3760 for support.
  • 175—AC power restored. No action necessary.
  • 177—Indoor temperature sensor error. Call Church Services at 713-396-3760 for help.
  • 178—Outdoor temperature sensor error. Reach Church Services at 713-396-3760 for support.
  • 181/182—Replace air filter. Clear the display by touching “dismiss” after adding a fresh filter.
  • 183—Clean humidifier tank and add a new water filter. Clear the display by hitting “dismiss” after finishing these procedures.
  • 184—Get a new humidifier pad. Clear the screen by touching “dismiss” after getting a new pad filter.
  • 185—Replace dehumidifier filter. Clear the screen by hitting “dismiss” after adding a new filter.
  • 186—Rinse ventilator core. Clear the thermostat by hitting “dismiss” after finishing this task.
  • 187—Wash or install a new ventilator filter. Clear the screen by tapping “dismiss” after getting a new filter.
  • 188/189—Get a new UV bulb. Reach Church Services at 713-396-3760 for help.
  • 210—Register online for outdoor temperature. Download the Lyric app to complete this step and ensure correct thermostat operation.
  • 388—Register online for remote access and outside 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. Download the Lyric app and follow the steps to connect your thermostat.

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

Our Experts are Ready to Provide Assistance

If you’re still experiencing troubles after working through the troubleshooting steps, our professionals are available to assist you. Give us a call at 713-396-3760 and we’ll be out as fast as we can to determine the problem.

If you rely on an aging thermostat, right now is a fantastic time to think over a replacement. Thermostat technology has come a long way lately Ask us for more information on how smart thermostats can make your house comfier while helping save on heating and cooling expenses throughout the year.

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