How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the leading thermostat producers, and we proudly install them on a regular basis in Austin. They’re long-lasting and reliable. In addition, Honeywell is frequently enhancing its technology, resulting in more features for your household.

However, every thermostat can experience troubles at one time or another. As a result, we’ve put together this valuable guidebook to go over troubleshooting. While Honeywell thermostat problems are rare, they do occur. 

While you can typically solve many thermostat issues by yourself, they often call for Expert support. Our heating and cooling pros are here to support you when you need us. We’re only a call away at 512-592-3072 .

Let’s start the process by determining what model of thermostat your residence has.

What Kind of Thermostat Do I Have?

There are three kinds of thermostats:

  • Manual—This is the older dial-shaped thermostat. You won’t run into error codes with this one, but it’s also the least efficient for lowering energy costs.
  • Programmable—This thermostat features a digital screen and arrows you use to determine your desired temperature. You can also use daily programs to decrease the temperature when you’re gone and increase it when you return.
  • Smart—You won’t have to make any programs on this thermostat, since it adjusts to your day. It intuitively changes the temperature when you or loved ones are away to help you save on heating and cooling expenses. You can also change 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 may take place. Most of these issues don’t require pro support and are easy to solve by yourself.

Common Honeywell Thermostat Issues

All thermostats have a unique group of codes matching the glitches that take place.

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

Here are some of the most encountered Honeywell thermostat problems. These include the following programmable thermostats:

Display is Blank

If the screen is empty on your programmable thermostat, you might need to put in new batteries. If that doesn’t take care of the malfunction or you rely on a smart thermostat, there might be a wiring issue.

Next, you should make sure the power is enabled for your furnace or air handler. Verify the switch by the indoor equipment is switched “up”.

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

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

While it’s less common, a blank screen could indicate you should buy a new thermostat.

Comfort System Won’t Start

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

In the summer, make sure you schedule the thermostat below the room temperature. In the winter, verify it’s higher. This sounds absurd, but we’ve seen it happen many times.

Confirm the power switch near your indoor equipment is in the “on” position. You should also make sure the cabinet doors or panels are secure on your furnace cabinet or air handler. An open panel can trip the safety switch, diverting power to the equipment.

Heating or cooling still won’t run? Make sure circuit breakers haven’t flipped and that your HVAC equipment isn’t displaying error codes.

“Cool On” or “Heat On” is Flashing

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

Then, make sure it’s signaling the correct unit to run. This is typically demonstrated by “cool on,” “heat on” or an icon.

If this set of words or the icon is pulsing, your thermostat is in a five-minute delay status. This feature protects your system from bad short cycling. This may occur if you lose electricity.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump needs service. Call Strand Brothers Service Experts at 512-592-3072 for support.
  • 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. Finish these settings so scheduling can occur.
  • 173—Thermostat temperature sensor error. Contact Lyric technical support at 800-633-3991.
  • 175—AC power restarted. No action necessary.
  • 181/182—Install a new air filter. Clear the monitor by touching “dismiss” after installing a clean filter.
  • 184—Put in a new humidifier pad. Clear the display by hitting “dismiss” after installing a clean pad filter.
  • 185—Replace dehumidifier filter. Clear the monitor by tapping “dismiss” after adding a clean filter.
  • 187—Clean or replace ventilator filter. Clear the thermostat by hitting “dismiss” after installing a fresh filter.
  • 188/189—Get a new UV bulb. Call Strand Brothers Service Experts at 512-592-3072 for support.
  • 210—Register online for exterior temperature. Download the Lyric app to do this step and ensure accurate thermostat operation.
  • 388—Register online for remote access and outdoor temperature. Get 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 select new Wi-Fi network.
  • 508—Wi-Fi not set up. Download the Lyric app and follow the procedure to connect your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump must be serviced service. Reach Strand Brothers Service Experts at 512-592-3072 for help.
  • 168—Wi-Fi radio error. Call Strand Brothers Service Experts at 512-592-3072 for support.
  • 170—Internal memory error. Reach Strand Brothers Service Experts at 512-592-3072 for help.
  • 171—Set date and time. Finalize these settings so scheduling can run.
  • 173—Thermostat temperature sensor error. Call Strand Brothers Service Experts at 512-592-3072 for assistance.
  • 175—AC power reconnected. No action necessary.
  • 177—Indoor temperature sensor error. Reach Strand Brothers Service Experts at 512-592-3072 for assistance.
  • 178—Outdoor temperature sensor error. Contact Strand Brothers Service Experts at 512-592-3072 for help.
  • 181/182—Install a new air filter. Clear the monitor by touching “dismiss” after putting in a clean filter.
  • 183—Clean humidifier tank and install a new water filter. Clear the screen by hitting “dismiss” after doing these steps.
  • 184—Get a new humidifier pad. Clear the display by touching “dismiss” after getting a new pad filter.
  • 185—Install a new dehumidifier filter. Clear the screen by touching “dismiss” after adding a fresh filter.
  • 186—Wash ventilator core. Clear the display by touching “dismiss” after doing this task.
  • 187—Clean or get a new ventilator filter. Clear the monitor by touching “dismiss” after buying a new filter.
  • 188/189—Get a new UV bulb. Reach Strand Brothers Service Experts at 512-592-3072 for help.
  • 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 outdoor temperature. Use the Lyric app to finish this step and ensure accurate 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 connected. 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 Available to Provide Assistance

If you’re still having issues after trying the troubleshooting list, our pros are ready to assist you. Call us at 512-592-3072 and we’ll be out rapidly to determine the problem.

If you use an aging thermostat, right now is a good time to consider a replacement. Thermostat technology has advanced over the last few years. Ask us for more details on how smart thermostats can make your house comfier while helping save on heating and cooling bills year-round.

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