How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the top thermostat brands, and we proudly install them on a regular basis in Fort Wayne. They’re long-lasting and trustworthy. Also, Honeywell is constantly advancing its technology, offering more features for your residence.

However, all thermostats can run into troubles at one time or another. Due to this, we’ve compiled this useful manual to run through troubleshooting.

While you can usually fix most thermostat troubles by yourself, they occasionally require Expert support. Our HVAC professionals are here to help when you need us. We’re just a call away at 260-557-1275.

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

What Type of Thermostat Do I Have?

There are three kinds of thermostats:

  • Manual—This is the typical dial-shaped thermostat. You won’t have error codes with this kind, but it’s also the least efficient for reducing energy bills.
  • Programmable—This thermostat includes a digital screen and arrows you touch to determine your desired temperature. You can also use daily programs to lower the temperature when you’re away and raise it when you return.
  • Smart—You won’t have to make any programs on this thermostat, since it adjusts to your schedule. It automatically adjusts the temperature when you or other household members are out and about to help you save on energy bills. You can also adjust the temperature anywhere using your phone or other Wi-Fi-enabled device. 

As you know the majority of technologically advanced things, there are common problems that may take place. Many of these situations don’t call for Expert assistance and are simple to solve by yourself.

Common Honeywell Thermostat Problems

Each thermostat has a unique kind of codes assigned to the issues that occur.

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

Here is a listing the most encountered Honeywell thermostat problems. These are applicable to the following programmable thermostats:

Display is Blank

If the monitor is empty on your programmable thermostat, you may need to get new batteries. If that doesn’t take care of the problem or you rely on a smart thermostat, there could be a wiring problem.

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

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

A loose panel may trigger the safety switch, which disconnects power to the equipment.

Infrequently, a clear display could indicate you will need to get a new thermostat.

Heating and Cooling Unit Won’t Run

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

When it’s hot, confirm you schedule the thermostat below the ambient temperature. When it’s cold, confirm it’s higher. This sounds goofy, but we’ve seen it happen a lot of times.

Make sure the power switch near your indoor equipment is in the “on” position. You should also comfirm the cabinet doors or panels are closed on your furnace cabinet or air handler. A loose panel can trip the safety switch, cutting off power to the system.

System still won’t run? Confirm circuit breakers haven’t turned off and that your HVAC equipment isn’t experiencing error codes.

“Cool On” or “Heat On” is Blinking

To begin, make sure your thermostat is switched to “cool” or “heat.”

Then, verify it’s telling the correct system to start. 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 feature protects your unit from harmful short cycling. This could occur if your power is interrupted.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump must be serviced. Call Rolf Griffin Service Experts at 260-557-1275 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 run.
  • 173—Thermostat temperature sensor error. Reach Lyric technical support at 800-633-3991.
  • 175—AC power resumed. No action needed.
  • 181/182—Install a new air filter. Clear the monitor by tapping “dismiss” after adding a new filter.
  • 184—Install a new humidifier pad. Clear the display by hitting “dismiss” after adding a fresh pad filter.
  • 185—Install a new dehumidifier filter. Clear the monitor by touching “dismiss” after adding a fresh filter.
  • 187—Clean or install a new ventilator filter. Clear the monitor by touching “dismiss” after installing a clean filter.
  • 188/189—Get a new UV bulb. Contact Rolf Griffin Service Experts at 260-557-1275 for help.
  • 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 exterior temperature. Get the Lyric app to do 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 configured. Use the Lyric app and follow the steps to configure your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump must be serviced service. Contact Rolf Griffin Service Experts at 260-557-1275 for support.
  • 168—Wi-Fi radio error. Reach Rolf Griffin Service Experts at 260-557-1275 for help.
  • 170—Internal memory error. Call Rolf Griffin Service Experts at 260-557-1275 for help.
  • 171—Set date and time. Finalize these settings so scheduling can operate.
  • 173—Thermostat temperature sensor error. Contact Rolf Griffin Service Experts at 260-557-1275 for help.
  • 175—AC power restored. No action needed.
  • 177—Indoor temperature sensor error. Contact Rolf Griffin Service Experts at 260-557-1275 for help.
  • 178—Outdoor temperature sensor error. Call Rolf Griffin Service Experts at 260-557-1275 for assistance.
  • 181/182—Get a new air filter. Clear the display by touching “dismiss” after adding a clean filter.
  • 183—Wash humidifier tank and install a new water filter. Clear the thermostat by tapping “dismiss” after doing these tasks.
  • 184—Get a new humidifier pad. Clear the display by hitting “dismiss” after installing pad filter.
  • 185—Get a new dehumidifier filter. Clear the thermostat by tapping “dismiss” after installing a fresh filter.
  • 186—Clean ventilator core. Clear the monitor by touching “dismiss” after finishing this task.
  • 187—Rinse or get a new ventilator filter. Clear the screen by tapping “dismiss” after installing a new filter.
  • 188/189—Add a new UV bulb. Get in touch with Rolf Griffin Service Experts at 260-557-1275 for assistance.
  • 210—Register online for exterior temperature. Get the Lyric app to finish this step and ensure correct thermostat operation.
  • 388—Register online for remote access and outside temperature. Get the Lyric app to finish 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 choose new Wi-Fi network.
  • 508—Wi-Fi not connected. Download the Lyric app and follow the procedures to connect your thermostat.

For more specifics, check this thermostat’s user manual.

Our Experts are Available to Provide Support

If you’re still having issues after working through the troubleshooting list, our Experts are available to support you. Call us at 260-557-1275 and we’ll arrive quickly to figure out the malfunction.

If you use an older thermostat, right now is a good time to think about a replacement. Thermostat technology has come a long way lately Ask us for more information on how smart thermostats can make your house comfier while helping save on heating and cooling costs throughout the year.

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