How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the top thermostat producers, and we proudly install them on a usual basis in Naples. They’re sturdy and trustworthy. Also, Honeywell is constantly updating its technology, offering more features for your house.

However, every thermostat can run into errors at one time or another. As a result, we’ve prepared this valuable manual to run through troubleshooting. While Honeywell thermostat problems are rare, they happen. 

While you can often repair most thermostat troubles by yourself, they sometimes call for Expert support. Our HVAC pros are here to help when you need us. We’re merely a call away at 239-908-6991.

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

What Model of Thermostat Do I Have?

There are three kinds of thermostats:

  • Manual—This is the older dial-shaped thermostat. You won’t have error codes with this type, but it’s also the least efficient for reducing heating and cooling expenses.
  • Programmable—This thermostat includes a digital screen and arrows you press to choose your desired temperature. You can also set daily programs to decrease the temperature when you’re away and set it higher when you get back.
  • Smart—You won’t have to schedule any programs on this thermostat, as it adjusts to your routine. It instinctively changes the temperature when you or loved ones are away to help you save on energy bills. You can also adjust the temperature anywhere via your phone or other Wi-Fi-enabled device. 

As is the case with most technologically advanced products, there are regular problems that may occur. The majority of of these problems don’t require pro help and are uncomplicated enough to fix on your own.

Common Honeywell Thermostat Troubles

Every thermostat has a special group of codes assigned to the glitches that take place.

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

Here is a guide to the most common Honeywell thermostat problems. These include the following programmable thermostats:

Display is Blank

If the display is blank on your programmable thermostat, you could need to replace the batteries. If that doesn’t solve the problem or you rely on a smart thermostat, there may be a wiring malfunction.

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

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

An unsecured panel may activate the safety switch, which cuts off power to the equipment.

Less frequently, a clear monitor could mean you will need to buy a new thermostat.

Heating and Cooling Unit Won’t Work

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

In the summer, make sure you set the thermostat lower than the ambient temperature. When it’s cold, confirm it’s higher. This sounds silly, 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 comfirm the cabinet doors or panels are secure on your furnace cabinet or air handler. A loose panel can trigger the safety switch, stopping electricity to the equipment.

Equipment still won’t turn on? Verify circuit breakers haven’t turned off and that your HVAC unit isn’t experiencing error codes.

“Cool On” or “Heat On” is Blinking

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

Then, check it’s calling for the correct equipment to start. This is often demonstrated by “cool on,” “heat on” or an illustration.

If this set of words or the icon is pulsing, your thermostat is in a five-minute delay state. This setting protects your equipment from harmful short cycling. This could occur if you lose power.

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 239-908-6991 for support.
  • 168—Wi-Fi radio error. Contact Lyric technical support at 800-633-3991. 170—Internal memory error. Contact Lyric technical support at 800-633-3991.
  • 171—Set date and time. Complete these settings so scheduling can take place.
  • 173—Thermostat temperature sensor error. Reach Lyric technical support at 800-633-3991.
  • 175—AC power restored. No action necessary.
  • 181/182—Install a new air filter. Clear the monitor by touching “dismiss” after installing a fresh filter.
  • 184—Install a new humidifier pad. Clear the display by tapping “dismiss” after installing a new pad filter.
  • 185—Put in a new dehumidifier filter. Clear the monitor by hitting “dismiss” after adding a clean filter.
  • 187—Rinse or install a new ventilator filter. Clear the thermostat by hitting “dismiss” after adding a fresh filter.
  • 188/189—Replace UV bulb. Call Service Experts Heating & Air Conditioning at 239-908-6991 for support.
  • 210—Register online for outside temperature. Download the Lyric app to do this step and ensure proper thermostat operation.
  • 388—Register online for remote access and exterior 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 set up. Download the Lyric app and follow the process to configure your thermostat.

For more information, see this thermostat’s user manual.

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump must be serviced service. Contact Service Experts Heating & Air Conditioning at 239-908-6991 for help.
  • 168—Wi-Fi radio error. Call Service Experts Heating & Air Conditioning at 239-908-6991 for assistance.
  • 170—Internal memory error. Contact Service Experts Heating & Air Conditioning at 239-908-6991 for support.
  • 171—Set date and time. Complete these settings so scheduling can run.
  • 173—Thermostat temperature sensor error. Reach Service Experts Heating & Air Conditioning at 239-908-6991 for assistance.
  • 175—AC power resumed. No action necessary.
  • 177—Indoor temperature sensor error. Call Service Experts Heating & Air Conditioning at 239-908-6991 for assistance.
  • 178—Outdoor temperature sensor error. Call Service Experts Heating & Air Conditioning at 239-908-6991 for help.
  • 181/182—Get a new air filter. Clear the screen by touching “dismiss” after putting in a new filter.
  • 183—Clean humidifier tank and install a new water filter. Clear the monitor by tapping “dismiss” after doing these procedures.
  • 184—Get a new humidifier pad. Clear the thermostat by touching “dismiss” after adding a new pad filter.
  • 185—Replace dehumidifier filter. Clear the screen by hitting “dismiss” after adding a clean filter.
  • 186—Clean ventilator core. Clear the thermostat by hitting “dismiss” after completing this task.
  • 187—Clean or get a new ventilator filter. Clear the monitor by touching “dismiss” after getting a new filter.
  • 188/189—Add a new UV bulb. Contact Service Experts Heating & Air Conditioning at 239-908-6991 for assistance.
  • 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. Download 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 choose new Wi-Fi network.
  • 508—Wi-Fi not configured. Get the Lyric app and follow the procedures 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 problems after working through the troubleshooting list, our pros are here to assist you. Reach us at 239-908-6991 and we’ll come to your house rapidly to figure out the malfunction.

If you use an older thermostat, now is a great time to think about a new device. Thermostat technology has advanced lately Ask us for more details on how smart thermostats can make your home more convenient while helping save on utility expenses all year.

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