How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the best thermostat brands, and we proudly install them on a usual basis in Roanoke. They’re sturdy and reliable. Also, Honeywell is regularly enhancing its technology, bringing more features for your residence.

Nevertheless, each thermostat can experience problems once in awhile. As a result, we’ve compiled this informative guide to walk you through troubleshooting.

While you can often fix the majority of thermostat issues alone, they occasionally require Expert help. Our home comfort pros are here to support you when you need us. We’re just a call away at 540-302-8645.

Let’s begin the process by figuring 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 typical dial-shaped thermostat. You won’t experience error codes with this kind, but it’s also the least efficient for reducing utility expenses.
  • Programmable—This thermostat features a digital screen and arrows you use to set your desired temperature. You can also set daily programs to reduce the temperature when you’re gone and increase it when you return.
  • Smart—You won’t have to set any programs on this thermostat, since it learns your routine. It instinctively adjusts the temperature when you or loved ones are gone to help you save on heating and cooling bills. You can also change the temperature anywhere using your phone or other Wi-Fi-enabled device. 

As is the case with most technologically advanced products, there are several malfunctions that may occur. Most of these troubles don’t require pro assistance and are uncomplicated enough to repair by yourself.

Common Honeywell Thermostat Troubles

Every thermostat has a unique group of codes matching the glitches that happen.

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

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

Display is Blank

If the display is clear on your programmable thermostat, you may need to install new batteries. If that doesn’t fix the malfunction or you use a smart thermostat, there may be a wiring problem.

Next, you should check the power is flowing for your furnace or air handler. Confirm the switch close to the indoor unit is in the “on” position.

Additionally, you should confirm all furnace cabinet or air handler doors/panels are securely in place.

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

Less frequently, an empty display may indicate you need to buy a new thermostat.

Comfort Equipment Won’t Run

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

In the summer, confirm you put the thermostat beneath the ambient temperature. In the winter, make sure it’s higher. This sounds goofy, but we’ve seen it happen a lot of times.

Ensure the power switch near 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, cutting off power to the equipment.

System still won’t turn on? Confirm circuit breakers haven’t flipped and that your HVAC equipment isn’t experiencing error codes.

“Cool On” or “Heat On” is Flashing

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

Then, ensure it’s calling for the correct unit to run. This is typically demonstrated by “cool on,” “heat on” or a picture.

If this set of words or the illustration is blinking, your thermostat is in a five-minute delay status. This setting keeps your unit from harmful 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 Service Experts Heating & Air Conditioning at 540-302-8645 for assistance.
  • 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. Finalize these settings so scheduling can run.
  • 173—Thermostat temperature sensor error. Reach Lyric technical support at 800-633-3991.
  • 175—AC power restarted. No action necessary.
  • 181/182—Replace air filter. Clear the screen by tapping “dismiss” after adding a clean filter.
  • 184—Replace humidifier pad. Clear the screen by touching “dismiss” after putting in a new pad filter.
  • 185—Put in a new dehumidifier filter. Clear the thermostat by touching “dismiss” after installing a new filter.
  • 187—Wash or replace ventilator filter. Clear the screen by hitting “dismiss” after adding a fresh filter.
  • 188/189—Get a new UV bulb. Call Service Experts Heating & Air Conditioning at 540-302-8645 for help.
  • 210—Register online for outside temperature. Use the Lyric app to complete this step and ensure accurate thermostat operation.
  • 388—Register online for remote access and outdoor temperature. Get the Lyric app to finish 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 pick new Wi-Fi network.
  • 508—Wi-Fi not configured. Get the Lyric app and follow the steps to configure your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump needs service. Call Service Experts Heating & Air Conditioning at 540-302-8645 for assistance.
  • 168—Wi-Fi radio error. Call Service Experts Heating & Air Conditioning at 540-302-8645 for help.
  • 170—Internal memory error. Contact Service Experts Heating & Air Conditioning at 540-302-8645 for assistance.
  • 171—Set date and time. Complete these settings so scheduling can work.
  • 173—Thermostat temperature sensor error. Call Service Experts Heating & Air Conditioning at 540-302-8645 for assistance.
  • 175—AC power restored. No action necessary.
  • 177—Indoor temperature sensor error. Reach Service Experts Heating & Air Conditioning at 540-302-8645 for support.
  • 178—Outdoor temperature sensor error. Contact Service Experts Heating & Air Conditioning at 540-302-8645 for assistance.
  • 181/182—Get a new air filter. Clear the monitor by touching “dismiss” after adding a fresh filter.
  • 183—Clean humidifier tank and install a new water filter. Clear the screen by tapping “dismiss” after doing these tasks.
  • 184—Replace humidifier pad. Clear the monitor by tapping “dismiss” after getting a new pad filter.
  • 185—Get a new dehumidifier filter. Clear the screen by tapping “dismiss” after adding a fresh filter.
  • 186—Clean ventilator core. Clear the thermostat by hitting “dismiss” after doing this task.
  • 187—Wash or install a new ventilator filter. Clear the monitor 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 540-302-8645 for support.
  • 210—Register online for outside temperature. Use the Lyric app to complete this step and ensure correct thermostat operation.
  • 388—Register online for remote access and outside temperature. Use the Lyric app to complete 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. Get the Lyric app and follow the procedures to connect your thermostat.

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

Our Experts are Here to Provide Assistance

If you’re still running into problems after going through the troubleshooting steps, our Experts are ready to help. Call us at 540-302-8645 and we’ll come to your house as fast as we can to determine the issue.

If you have an aging thermostat, now is a good time to think over 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 comfier while helping save on utility costs year-round.

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