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 sturdy and dependable. Also, Honeywell is constantly enhancing its technology, offering more features for your house.

Still, each thermostat can have issues now and again. Due to this, we’ve compiled this useful guide to go over troubleshooting.

While you can typically repair the majority of thermostat issues alone, they sometimes call for Expert assistance. Our home comfort professionals are available to assist you when you need us. We’re only a call away at 289-273-2229.

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

What Model of Thermostat Do I Have?

There are three types of thermostats:

  • Manual—This is the typical dial-shaped thermostat. You won’t run into error codes with this type, but it’s also the least efficient for reducing energy costs.
  • Programmable—This thermostat features a digital screen and arrows you press to determine your desired temperature. You can also choose daily programs to decrease the temperature when you’re gone and set it higher when you return.
  • Smart—You won’t have to set any programs on this thermostat, since it learns your day. It instinctively adjusts the temperature when you or family members are away to help you save on utility bills. You can also adjust the temperature anywhere on your phone or other Wi-Fi-enabled device. 

As you know most technologically advanced solutions, there are regular malfunctions that can occur. Many of these problems don’t require Expert assistance and are uncomplicated enough to repair alone.

Common Honeywell Thermostat Problems

All thermostats have a special set of codes that correspond to the troubles that happen.

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

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 fix the malfunction or you use a smart thermostat, there might be a wiring problem.

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 activate the safety switch, which stops power to the equipment.

While it’s less common, an empty monitor could mean you should replace your thermostat.

Heating and Cooling Unit Won’t Start

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

When it’s hot, confirm you put the thermostat below the room temperature. When it’s cool, 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 closed 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 run? Verify circuit breakers haven’t turned off and that your HVAC system isn’t displaying error codes.

“Cool On” or “Heat On” is Flickering

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

Then, make sure it’s signaling 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 occur if your power is interrupted.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump needs service. Call Service Experts Heating & Air Conditioning 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. Finalize these settings so scheduling can run.
  • 173—Thermostat temperature sensor error. Call Lyric technical support at 800-633-3991.
  • 175—AC power restarted. No action necessary.
  • 181/182—Replace air filter. Clear the monitor by tapping “dismiss” after putting in a clean filter.
  • 184—Install a new humidifier pad. Clear the screen by touching “dismiss” after putting in a clean pad filter.
  • 185—Put in a new dehumidifier filter. Clear the display by touching “dismiss” after putting in a clean filter.
  • 187—Rinse or install a new ventilator filter. Clear the screen by touching “dismiss” after putting in a new filter.
  • 188/189—Replace UV bulb. Contact Service Experts Heating & Air Conditioning at 289-273-2229 for support.
  • 210—Register online for outdoor temperature. Get 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 accurate thermostat operation.
  • 399—No Internet. Confirm 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, look at this thermostat’s user manual.

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump needs service. Reach Service Experts Heating & Air Conditioning at 289-273-2229 for support.
  • 168—Wi-Fi radio error. Reach Service Experts Heating & Air Conditioning at 289-273-2229 for help.
  • 170—Internal memory error. Reach Service Experts Heating & Air Conditioning at 289-273-2229 for assistance.
  • 171—Set date and time. Finish these settings so scheduling can run.
  • 173—Thermostat temperature sensor error. Call Service Experts Heating & Air Conditioning at 289-273-2229 for help.
  • 175—AC power resumed. No action needed.
  • 177—Indoor temperature sensor error. Call Service Experts Heating & Air Conditioning at 289-273-2229 for assistance.
  • 178—Outdoor temperature sensor error. Contact Service Experts Heating & Air Conditioning at 289-273-2229 for assistance.
  • 181/182—Get a new air filter. Clear the thermostat by tapping “dismiss” after putting in 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 hitting “dismiss” after adding a fresh filter.
  • 186—Clean ventilator core. Clear the monitor by touching “dismiss” after doing this task.
  • 187—Rinse or install a new ventilator filter. Clear the screen by touching “dismiss” after buying a new filter.
  • 188/189—Get a new UV bulb. Reach Service Experts Heating & Air Conditioning at 289-273-2229 for help.
  • 210—Register online for outside temperature. Get the Lyric app to do this step and ensure correct 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 set up. Get the Lyric app and follow the process to connect your thermostat.

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

Our Experts are Ready to Provide Support

If you’re still running into problems after working through the troubleshooting steps, our professionals are available to support you. Call 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 great time to consider a replacement. Thermostat technology has come a long way lately Ask us for more details on how smart thermostats can make your home comfier while helping save on energy bills year-round.

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