How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the best thermostat manufacturers, and we proudly install them on a regular basis in Hillsborough. They’re long-lasting and reliable. Plus, Honeywell is constantly improving its technology, resulting in more features for your household.

However, every thermostat can have problems occasionally. As a result, we’ve compiled this helpful guide to run through troubleshooting.

While you can usually repair the majority of thermostat issues alone, they occasionally call for Expert help. Our home comfort professionals are here to help when you need us. We’re only a call away at 908-448-2154.

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

What Type of Thermostat Do I Have?

There are three models of thermostats:

  • Manual—This is the typical dial-shaped thermostat. You won’t have error codes with this one, but it’s also the least efficient for reducing energy bills.
  • Programmable—This thermostat has a digital screen and arrows you use to choose your desired temperature. You can also use daily programs to decrease the temperature when you’re at work and increase it when you return.
  • Smart—You won’t have to make any programs on this thermostat, because it adjusts to your routine. It automatically raises and lowers the temperature when you or family members are out and about to help you save on energy costs. You can also raise or lower the temperature anywhere via your phone or other Wi-Fi-enabled device. 

As you know most technologically advanced solutions, there are several glitches that may take place. The majority of of these situations don’t call for professional support and are easy to repair on your own.

Common Honeywell Thermostat Problems

Each thermostat has a special kind of codes matching the malfunctions that occur.

Think how easy it can be to repair a computer by restarting it. For the most part, troubleshooting a thermostat can be just as simple.

Here are some of the most encountered Honeywell thermostat issues. These are applicable to the following programmable thermostats:

Display is Blank

If the monitor is blank on your programmable thermostat, you could need to get new batteries. If that doesn’t take care of the problem or you use a smart thermostat, there may be a wiring malfunction.

Next, you should check the power is on for your furnace or air handler. Confirm the switch by the indoor unit is switched “up”.

In addition to that, you should make sure all furnace cabinet or air handler doors/panels are sturdily fastened.

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

While it’s less common, a blank monitor may mean you will need to install a new thermostat.

HVAC System Won’t Turn On

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

When it’s hot, verify you put the thermostat lower than the current temperature. When it’s cold, make sure it’s higher. This sounds goofy, but we’ve seen it happen many times.

Ensure the power switch near your indoor equipment is in the “on” position. You should also comfirm the cabinet doors or panels are secure on your furnace cabinet or air handler. A loose panel can activate the safety switch, diverting power to the system.

System still won’t turn on? Make sure circuit breakers haven’t tripped and that your HVAC system isn’t displaying error codes.

“Cool On” or “Heat On” is Blinking

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

Then, make sure it’s calling for the correct system to turn on. This is often shown by “cool on,” “heat on” or a picture.

If this phrase or the picture is pulsing, your thermostat is in a five-minute delay state. This feature stops your system from harmful short cycling. This can occur if you lose electricity.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump needs service. Call Fras-Air/General Service Experts at 908-448-2154 for help.
  • 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 run.
  • 173—Thermostat temperature sensor error. Reach Lyric technical support at 800-633-3991.
  • 175—AC power resumed. No action necessary.
  • 181/182—Put in a new air filter. Clear the monitor by hitting “dismiss” after installing a new filter.
  • 184—Put in a new humidifier pad. Clear the thermostat by tapping “dismiss” after installing a clean pad filter.
  • 185—Replace dehumidifier filter. Clear the thermostat by touching “dismiss” after putting in a clean filter.
  • 187—Clean or put in a new ventilator filter. Clear the thermostat by tapping “dismiss” after putting in a new filter.
  • 188/189—Install a new UV bulb. Contact Fras-Air/General Service Experts at 908-448-2154 for assistance.
  • 210—Register online for exterior temperature. Get the Lyric app to do this step and ensure accurate thermostat operation.
  • 388—Register online for remote access and outside temperature. Get 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 select new Wi-Fi network.
  • 508—Wi-Fi not set up. Get the Lyric app and follow the procedure to link your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump requires service. Call Fras-Air/General Service Experts at 908-448-2154 for help.
  • 168—Wi-Fi radio error. Call Fras-Air/General Service Experts at 908-448-2154 for assistance.
  • 170—Internal memory error. Reach Fras-Air/General Service Experts at 908-448-2154 for help.
  • 171—Set date and time. Complete these settings so scheduling can work.
  • 173—Thermostat temperature sensor error. Call Fras-Air/General Service Experts at 908-448-2154 for support.
  • 175—AC power resumed. No action required.
  • 177—Indoor temperature sensor error. Call Fras-Air/General Service Experts at 908-448-2154 for help.
  • 178—Outdoor temperature sensor error. Contact Fras-Air/General Service Experts at 908-448-2154 for assistance.
  • 181/182—Replace air filter. Clear the thermostat by tapping “dismiss” after putting in a clean filter.
  • 183—Rinse humidifier tank and replace water filter. Clear the screen by tapping “dismiss” after doing these procedures.
  • 184—Install a new humidifier pad. Clear the monitor by tapping “dismiss” after getting a new pad filter.
  • 185—Replace dehumidifier filter. Clear the monitor by tapping “dismiss” after adding a new filter.
  • 186—Rinse ventilator core. Clear the display by tapping “dismiss” after finishing this task.
  • 187—Wash or get a new ventilator filter. Clear the monitor by hitting “dismiss” after buying a new filter.
  • 188/189—Add a new UV bulb. Get in touch with Fras-Air/General Service Experts at 908-448-2154 for assistance.
  • 210—Register online for outside temperature. Download the Lyric app to do 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. Confirm 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. Download the Lyric app and follow the process to connect your thermostat.

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

Our Experts are Here to Provide Support

If you’re still experiencing troubles after working through the troubleshooting list, our Experts are available to support you. Call us at 908-448-2154 and we’ll arrive rapidly to figure out the malfunction.

If you rely on a dated thermostat, today is a fantastic time to think over a new thermostat. Thermostat technology has gotten better lately Ask us for more information on how smart thermostats can make your house more comfortable while helping save on energy costs all year.

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