How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the top thermostat brands, and we proudly install them on a regular basis in Ocala. They’re durable and reliable. Plus, Honeywell is frequently enhancing its technology, bringing more features for your family.

Nevertheless, each thermostat can experience errors at times. That’s why we’ve prepared this informative handbook to walk you through troubleshooting.

While you can usually solve many thermostat issues by yourself, they sometimes need Expert support. Our heating and cooling pros are here to support you when you need us. We’re only a call away at 352-414-4006.

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

What Kind of Thermostat Do I Have?

There are three models of thermostats:

  • Manual—This is the older dial-shaped thermostat. You won’t experience error codes with this type, but it’s also the least efficient for reducing utility expenses.
  • Programmable—This thermostat includes 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 raise it when you come home.
  • Smart—You won’t have to schedule any programs on this thermostat, since it picks up on your day. It automatically adjusts the temperature when you or family members are out and about to help you save on heating and cooling bills. You can also change the temperature anywhere using your phone or other Wi-Fi-enabled device. 

As you’re aware the majority of technologically advanced products, there are several glitches that can happen. The majority of of these situations don’t require pro support and are uncomplicated enough to solve alone.

Common Honeywell Thermostat Troubles

All thermostats have an exclusive kind of codes assigned to the issues that occur.

Think how easy it can be to repair a computer by restarting it. Many times, correcting a thermostat can be just as simple.

Here is a guide to the most common Honeywell thermostat issues. These are applicable to the following programmable thermostats:

Display is Blank

If the screen is empty on your programmable thermostat, you may need to install new batteries. If that doesn’t take care of the malfunction or you use a smart thermostat, there may be a wiring problem.

Next, you should check the power is flowing for your furnace or air handler. Make sure the switch by the indoor system is in the “on” position.

Additionally, you should confirm all furnace cabinet or air handler doors/panels are sturdily in place.

An unsecured panel may activate the safety switch, which disconnects power to the system.

Infrequently, a blank monitor could signify you will need to get a new thermostat.

HVAC Equipment Won’t Start

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

When it’s hot, make sure you put the thermostat lower than the room temperature. When it’s cold, make sure it’s higher. This sounds absurd, but we’ve seen it take place many times.

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

Equipment still won’t run? Make sure circuit breakers haven’t flipped and that your HVAC unit isn’t displaying error codes.

“Cool On” or “Heat On” is Flickering

First, verify your thermostat is set to “cool” or “heat.”

Then, ensure it’s signaling the correct unit to start. This is typically indicated by “cool on,” “heat on” or an illustration.

If this set of words or the picture is blinking, your thermostat is in a five-minute delay state. This setting protects your equipment from damaging short cycling. This may 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 Service Experts Heating & Air Conditioning at 352-414-4006 for help.
  • 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 occur.
  • 173—Thermostat temperature sensor error. Reach Lyric technical support at 800-633-3991.
  • 175—AC power restarted. No action required.
  • 181/182—Install a new air filter. Clear the display by touching “dismiss” after installing a new filter.
  • 184—Replace humidifier pad. Clear the display by hitting “dismiss” after putting in a fresh pad filter.
  • 185—Install a new dehumidifier filter. Clear the display by hitting “dismiss” after installing a fresh filter.
  • 187—Clean or install a new ventilator filter. Clear the monitor by tapping “dismiss” after adding a clean filter.
  • 188/189—Get a new UV bulb. Ring Service Experts Heating & Air Conditioning at 352-414-4006 for help.
  • 210—Register online for outside temperature. Download the Lyric app to do this step and ensure accurate 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. 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 steps to configure your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump needs service. Reach Service Experts Heating & Air Conditioning at 352-414-4006 for assistance.
  • 168—Wi-Fi radio error. Call Service Experts Heating & Air Conditioning at 352-414-4006 for help.
  • 170—Internal memory error. Call Service Experts Heating & Air Conditioning at 352-414-4006 for support.
  • 171—Set date and time. Finalize these settings so scheduling can work.
  • 173—Thermostat temperature sensor error. Contact Service Experts Heating & Air Conditioning at 352-414-4006 for assistance.
  • 175—AC power reconnected. No action needed.
  • 177—Indoor temperature sensor error. Reach Service Experts Heating & Air Conditioning at 352-414-4006 for help.
  • 178—Outdoor temperature sensor error. Call Service Experts Heating & Air Conditioning at 352-414-4006 for help.
  • 181/182—Install a new air filter. Clear the thermostat by tapping “dismiss” after putting in a new filter.
  • 183—Clean humidifier tank and replace water filter. Clear the monitor by hitting “dismiss” after completing these procedures.
  • 184—Replace humidifier pad. Clear the thermostat by tapping “dismiss” after installing pad filter.
  • 185—Replace dehumidifier filter. Clear the display by touching “dismiss” after putting in a fresh filter.
  • 186—Clean ventilator core. Clear the thermostat by touching “dismiss” after doing this task.
  • 187—Rinse or replace ventilator filter. Clear the display by touching “dismiss” after installing a new filter.
  • 188/189—Install a new UV bulb. Reach Service Experts Heating & Air Conditioning at 352-414-4006 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 outside temperature. Use the Lyric app to complete 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 pick new Wi-Fi network.
  • 508—Wi-Fi not set up. Get the Lyric app and follow the process to connect your thermostat.

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

Our Experts are Available to Provide Support

If you’re still having problems after going through the troubleshooting list, our professionals are ready to help. Give us a call at 352-414-4006 and we’ll arrive rapidly to figure out the problem.

If you rely on an older thermostat, right now is a great time to think over a replacement. Thermostat technology has gotten better over the last few years. Ask us for more details on how smart thermostats can make your home more convenient while helping save on energy bills year-round.

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