How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the best thermostat brands, and we proudly install them on a regular basis in Girard. They’re durable and dependable. Also, Honeywell is frequently advancing its technology, resulting in more features for your residence.

However, all thermostats can experience issues now and then. That’s why we’ve compiled this useful guidebook to run through troubleshooting. While Honeywell thermostat problems are rare, they do occur. 

While you can typically repair most thermostat issues on your own, they occasionally require Expert help. Our heating and cooling professionals are ready to support you when you need us. We’re just a call away at 330-269-7235.

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

What Model of Thermostat Do I Have?

There are three types of thermostats:

  • Manual—This is the older dial-shaped thermostat. You won’t run into error codes with this kind, but it’s also the least efficient for saving on utility expenses.
  • Programmable—This thermostat features a digital screen and arrows you press to set your desired temperature. You can also use daily programs to decrease the temperature when you’re gone and set it higher when you get back.
  • Smart—You won’t have to schedule any programs on this thermostat, since it learns your schedule. It instinctively raises and lowers the temperature when you or loved ones are out and about to help you save on utility expenses. You can also change the temperature anywhere using your phone or other Wi-Fi-enabled device. 

As you’re aware most technologically advanced solutions, there are regular problems that can take place. Many of these situations don’t need Expert help and are uncomplicated enough to repair on your own.

Common Honeywell Thermostat Problems

Each thermostat has an exclusive group of codes assigned to the problems that happen.

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

Here is a guide to the most encountered Honeywell thermostat errors. These apply to the following programmable thermostats:

Display is Blank

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

Next, you should make sure the power is enabled for your furnace or air handler. Verify the switch near the indoor unit is switched “on”.

In addition to that, you should make certain all furnace cabinet or air handler doors/panels are tightly in place.

A loose panel may trip the safety switch, which cuts off power to the equipment.

While it’s less common, a clear display can signify you need to install a new thermostat.

Comfort Equipment Won’t Work

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

When it’s hot, confirm you put the thermostat beneath the ambient temperature. When it’s cold, confirm it’s higher. This sounds goofy, but we’ve seen it take place a lot of times.

Ensure the power switch close to your indoor unit is in the “on” position. You should also check the cabinet doors or panels are tight on your furnace cabinet or air handler. A loose panel can trigger the safety switch, stopping power to the system.

Heating or cooling still won’t run? Confirm circuit breakers haven’t tripped and that your HVAC unit isn’t experiencing error codes.

“Cool On” or “Heat On” is Flickering

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

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

If this phrase or the illustration is blinking, your thermostat is in a five-minute delay status. This feature stops 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 needs service. Call Service Experts Heating & Air Conditioning at 330-269-7235 for support.
  • 168—Wi-Fi radio error. Contact 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 take place.
  • 173—Thermostat temperature sensor error. Contact Lyric technical support at 800-633-3991.
  • 175—AC power restarted. No action needed.
  • 181/182—Install a new air filter. Clear the display by touching “dismiss” after installing a fresh filter.
  • 184—Put in a new humidifier pad. Clear the display by tapping “dismiss” after installing a clean pad filter.
  • 185—Put in a new dehumidifier filter. Clear the thermostat by touching “dismiss” after putting in a fresh filter.
  • 187—Clean or put in a new ventilator filter. Clear the monitor by tapping “dismiss” after installing a clean filter.
  • 188/189—Install a new UV bulb. Call Service Experts Heating & Air Conditioning at 330-269-7235 for support.
  • 210—Register online for outside temperature. Get the Lyric app to complete this step and ensure proper thermostat operation.
  • 388—Register online for remote access and outside temperature. Use the Lyric app to finish this step and ensure proper 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 set up. Use the Lyric app and follow the procedure to connect your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump must be serviced service. Reach Service Experts Heating & Air Conditioning at 330-269-7235 for assistance.
  • 168—Wi-Fi radio error. Call Service Experts Heating & Air Conditioning at 330-269-7235 for support.
  • 170—Internal memory error. Call Service Experts Heating & Air Conditioning at 330-269-7235 for help.
  • 171—Set date and time. Complete these settings so scheduling can operate.
  • 173—Thermostat temperature sensor error. Call Service Experts Heating & Air Conditioning at 330-269-7235 for assistance.
  • 175—AC power resumed. No action necessary.
  • 177—Indoor temperature sensor error. Contact Service Experts Heating & Air Conditioning at 330-269-7235 for assistance.
  • 178—Outdoor temperature sensor error. Reach Service Experts Heating & Air Conditioning at 330-269-7235 for assistance.
  • 181/182—Get a new air filter. Clear the thermostat by touching “dismiss” after installing a clean filter.
  • 183—Wash humidifier tank and replace water filter. Clear the screen by touching “dismiss” after doing these procedures.
  • 184—Get a new humidifier pad. Clear the monitor by tapping “dismiss” after installing pad filter.
  • 185—Replace dehumidifier filter. Clear the display by hitting “dismiss” after adding a clean filter.
  • 186—Wash ventilator core. Clear the display by tapping “dismiss” after completing this task.
  • 187—Rinse or replace ventilator filter. Clear the display by tapping “dismiss” after getting a new filter.
  • 188/189—Add a new UV bulb. Get in touch with Service Experts Heating & Air Conditioning at 330-269-7235 for assistance.
  • 210—Register online for exterior temperature. Get the Lyric app to finish this step and ensure proper 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. Check 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. Get the Lyric app and follow the procedures to connect your thermostat.

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

Our Experts are Ready to Help

If you’re still running into issues after going through the troubleshooting process, our pros are available to help. Give us a call at 330-269-7235 and we’ll be out rapidly to determine the issue.

If you rely on a dated thermostat, today is a great time to think about a new thermostat. Thermostat technology has come a long way in recent years Ask us for more info on how smart thermostats can make your house more convenient while helping save on heating and cooling expenses throughout the year.

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