How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the best thermostat manufacturers, and we proudly install them on a frequent basis in the Niagara Region. They’re long-lasting and dependable. Also, Honeywell is constantly enhancing its technology, bringing more features for your residence.

Nevertheless, each thermostat can have errors every so often. Due to this, we’ve put together this useful guide to run through troubleshooting. While Honeywell thermostat problems are rare, they happen. 

While you can often repair many thermostat issues alone, they sometimes call for Expert assistance. Our home comfort Experts are here to support you when you need us. We’re only a call away at 289-273-2229.

Let’s start the process by figuring out what model of thermostat your home has.

What Type 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 reducing utility costs.
  • Programmable—This thermostat features a digital screen and arrows you press to determine your desired temperature. You can also choose daily programs to lower the temperature when you’re away and set it higher when you return.
  • Smart—You won’t have to set any programs on this thermostat, as it learns your day. It automatically adjusts the temperature when you or loved ones are away to help you save on utility bills. You can also adjust the temperature anywhere using your phone or other Wi-Fi-enabled device. 

As you’re aware most technologically advanced things, there are several malfunctions that can occur. Many of these problems don’t require Expert assistance and are uncomplicated enough to repair by yourself.

Common Honeywell Thermostat Problems

All thermostats have a special set of codes that correspond to the problems that take place.

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

Here is a listing the most reported Honeywell thermostat issues. These involve the following programmable thermostats:

Display is Blank

If the screen is blank on your programmable thermostat, you might need to put in new batteries. If that doesn’t solve the malfunction or you use a smart thermostat, there might be a wiring issue.

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

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

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

While it’s less common, an empty monitor could mean you will need to get a new 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 beneath the ambient temperature. When it’s cold, make sure it’s higher. This sounds absurd, but we’ve seen it occur many times.

Make sure the power switch by your indoor equipment is in the “on” position. You should also make sure the cabinet doors or panels are tight on your furnace cabinet or air handler. An unsecured panel can activate the safety switch, cutting off power to the unit.

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

“Cool On” or “Heat On” is Flickering

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

Then, make sure it’s telling the right equipment to run. This is typically indicated by “cool on,” “heat on” or an icon.

If this set of words or the icon is flashing, your thermostat is in a five-minute delay status. This setting protects your system from harmful short cycling. This can take place if your power is interrupted.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump requires service. Call Service Experts Home Services by Enercare at 289-273-2229 for support.
  • 168—Wi-Fi radio error. Call Lyric technical support at 800-633-3991. 170—Internal memory error. Call Lyric technical support at 800-633-3991.
  • 171—Set date and time. Finish 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 needed.
  • 181/182—Replace air filter. Clear the thermostat by hitting “dismiss” after adding a clean filter.
  • 184—Put in a new humidifier pad. Clear the screen by touching “dismiss” after putting in a fresh pad filter.
  • 185—Install a new dehumidifier filter. Clear the display by touching “dismiss” after adding a clean filter.
  • 187—Wash or install a new ventilator filter. Clear the monitor by touching “dismiss” after adding a new filter.
  • 188/189—Replace UV bulb. Contact Service Experts Home Services by Enercare at 289-273-2229 for support.
  • 210—Register online for outdoor temperature. Use the Lyric app to do this step and ensure proper thermostat operation.
  • 388—Register online for remote access and exterior temperature. Download 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 configured. Download the Lyric app and follow the steps to connect your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump needs service. Contact Service Experts Home Services by Enercare at 289-273-2229 for help.
  • 168—Wi-Fi radio error. Contact Service Experts Home Services by Enercare at 289-273-2229 for help.
  • 170—Internal memory error. Contact Service Experts Home Services by Enercare at 289-273-2229 for assistance.
  • 171—Set date and time. Finalize these settings so scheduling can run.
  • 173—Thermostat temperature sensor error. Call Service Experts Home Services by Enercare at 289-273-2229 for support.
  • 175—AC power resumed. No action necessary.
  • 177—Indoor temperature sensor error. Call Service Experts Home Services by Enercare at 289-273-2229 for assistance.
  • 178—Outdoor temperature sensor error. Contact Service Experts Home Services by Enercare at 289-273-2229 for assistance.
  • 181/182—Get a new air filter. Clear the thermostat by hitting “dismiss” after adding a fresh filter.
  • 183—Rinse humidifier tank and replace water filter. Clear the display by hitting “dismiss” after completing these tasks.
  • 184—Get a new humidifier pad. Clear the display by hitting “dismiss” after installing pad filter.
  • 185—Install a new dehumidifier filter. Clear the monitor by tapping “dismiss” after putting in a clean filter.
  • 186—Clean ventilator core. Clear the monitor by touching “dismiss” after doing this task.
  • 187—Wash or get a new ventilator filter. Clear the screen by touching “dismiss” after getting a new filter.
  • 188/189—Replace UV bulb. Get in touch with Service Experts Home Services by Enercare at 289-273-2229 for support.
  • 210—Register online for outside temperature. Get the Lyric app to finish this step and ensure accurate thermostat operation.
  • 388—Register online for remote access and outdoor temperature. Use the Lyric app to complete this step and ensure correct 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 connected. Use the Lyric app and follow the process to connect your thermostat.

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

Our Experts are Ready to Provide Support

If you’re still experiencing problems after working through the troubleshooting steps, our professionals are ready to support you. Reach us at 289-273-2229 and we’ll be out quickly to diagnose the issue.

If you rely on an aging thermostat, today is a fantastic time to consider a replacement. Thermostat technology has come a long way in recent years Ask us for more details on how smart thermostats can make your home comfier while helping save on utility bills year-round.

Contact Us