How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the top thermostat manufacturers, and we proudly install them on a regular basis in Edmonton. They’re durable and trustworthy. Plus, Honeywell is regularly advancing its technology, bringing more features for your home.

Nevertheless, each thermostat can experience errors occasionally. Due to this, we’ve compiled this helpful guidebook to run through troubleshooting.

While you can usually fix most thermostat problems by yourself, they occasionally require Expert support. Our heating and cooling Experts are available to support you when you need us. We’re merely a call away at 780-800-7092.

Let’s get started with the process by determining what type of thermostat your house has.

What Type of Thermostat Do I Have?

There are three types of thermostats:

  • Manual—This is the classic 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 includes 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 away and raise it when you return.
  • Smart—You won’t have to set any programs on this thermostat, as it learns your day. It intuitively changes the temperature when you or other household members are out and about to help you save on heating and cooling bills. You can also raise or lower the temperature anywhere on your phone or other Wi-Fi-enabled device. 

As you know the majority of technologically advanced things, there are several glitches that can happen. Most of these problems don’t call for pro help and are easy to repair on your own.

Common Honeywell Thermostat Troubles

All thermostats have an exclusive set of codes that correspond to the glitches that occur.

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

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

Display is Blank

If the display is blank on your programmable thermostat, you could need to install new batteries. If that doesn’t take care of the malfunction or you have a smart thermostat, there might be a wiring problem.

Next, you should ensure the power is flowing for your furnace or air handler. Confirm the switch close to the indoor equipment is switched “on”.

Additionally, you should make certain all furnace cabinet or air handler doors/panels are sturdily secured.

An unsecured panel may trigger the safety switch, which stops power to the unit.

While it’s less common, an empty display might signify you will need to get a new thermostat.

HVAC Equipment Won’t Work

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

In the summer, confirm you set the thermostat lower than the ambient temperature. When it’s cold, verify it’s higher. This sounds silly, but we’ve seen it occur a lot of 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, diverting electricity to the unit.

Unit still won’t turn on? Confirm circuit breakers haven’t turned off and that your HVAC equipment isn’t displaying error codes.

“Cool On” or “Heat On” is Flashing

To start, ensure your thermostat is set to “cool” or “heat.”

Then, make sure it’s telling the appropriate unit to turn on. This is typically shown by “cool on,” “heat on” or an icon.

If these words or the picture is pulsing, your thermostat is in a five-minute delay mode. This mode stops 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 McKinley Heating Service Experts at 780-800-7092 for assistance.
  • 168—Wi-Fi radio error. Call Lyric technical support at 800-633-3991. 170—Internal memory error. Reach Lyric technical support at 800-633-3991.
  • 171—Set date and time. Complete these settings so scheduling can run.
  • 173—Thermostat temperature sensor error. Contact Lyric technical support at 800-633-3991.
  • 175—AC power restored. No action required.
  • 181/182—Replace air filter. Clear the thermostat by touching “dismiss” after putting in a fresh filter.
  • 184—Put in a new humidifier pad. Clear the screen by tapping “dismiss” after adding a fresh pad filter.
  • 185—Install a new dehumidifier filter. Clear the thermostat by touching “dismiss” after adding a new filter.
  • 187—Wash or put in a new ventilator filter. Clear the screen by tapping “dismiss” after adding a clean filter.
  • 188/189—Install a new UV bulb. Contact McKinley Heating Service Experts at 780-800-7092 for help.
  • 210—Register online for exterior temperature. Download the Lyric app to finish this step and ensure proper thermostat operation.
  • 388—Register online for remote access and exterior temperature. Use the Lyric app to do 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 set up. Download the Lyric app and follow the steps to configure 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. Call McKinley Heating Service Experts at 780-800-7092 for assistance.
  • 168—Wi-Fi radio error. Contact McKinley Heating Service Experts at 780-800-7092 for help.
  • 170—Internal memory error. Contact McKinley Heating Service Experts at 780-800-7092 for help.
  • 171—Set date and time. Finalize these settings so scheduling can run.
  • 173—Thermostat temperature sensor error. Contact McKinley Heating Service Experts at 780-800-7092 for assistance.
  • 175—AC power resumed. No action needed.
  • 177—Indoor temperature sensor error. Reach McKinley Heating Service Experts at 780-800-7092 for help.
  • 178—Outdoor temperature sensor error. Reach McKinley Heating Service Experts at 780-800-7092 for support.
  • 181/182—Get a new air filter. Clear the monitor by hitting “dismiss” after putting in a fresh filter.
  • 183—Clean humidifier tank and install a new water filter. Clear the display by hitting “dismiss” after completing these procedures.
  • 184—Get a new humidifier pad. Clear the monitor by touching “dismiss” after getting a new pad filter.
  • 185—Replace dehumidifier filter. Clear the monitor by hitting “dismiss” after installing a new filter.
  • 186—Wash ventilator core. Clear the display by hitting “dismiss” after finishing this task.
  • 187—Wash or replace ventilator filter. Clear the display by hitting “dismiss” after buying a new filter.
  • 188/189—Add a new UV bulb. Contact McKinley Heating Service Experts at 780-800-7092 for help.
  • 210—Register online for outdoor temperature. Use the Lyric app to complete this step and ensure proper thermostat operation.
  • 388—Register online for remote access and outdoor temperature. Get the Lyric app to complete 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. Use the Lyric app and follow the procedures to connect your thermostat.

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

Our Experts are Here to Help

If you’re still running into problems after working through the troubleshooting list, our Experts are ready to support you. Reach us at 780-800-7092 and we’ll come to your house quickly to diagnose the issue.

If you rely on an aging thermostat, today is a fantastic time to think about a new device. Thermostat technology has gotten better in recent years Ask us for more info on how smart thermostats can make your home more comfortable while helping save on heating and cooling bills year-round.

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