How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the leading 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 residence.

However, each thermostat can run into issues at one time or another. Due to this, we’ve prepared this valuable guide to run through troubleshooting.

While you can typically solve most thermostat troubles alone, they sometimes need Expert help. 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 finding out what model of thermostat your residence 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 kind, but it’s also the least efficient for reducing heating and cooling costs.
  • Programmable—This thermostat features a digital screen and arrows you press to determine your desired temperature. You can also set daily programs to lower the temperature when you’re away and set it higher when you return.
  • Smart—You won’t have to schedule any programs on this thermostat, as it picks up on your routine. It instinctively raises and lowers the temperature when you or family members are away to help you save on heating and cooling 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 several problems that might occur. Most of these problems don’t require pro help and are uncomplicated enough to fix on your own.

Common Honeywell Thermostat Issues

All thermostats have an exclusive kind of codes assigned to the glitches that take place.

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

Here is a listing the most common Honeywell thermostat problems. These apply to 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 fix the problem or you use a smart thermostat, there could be a wiring malfunction.

Next, you should check the power is flowing for your furnace or air handler. Make sure the switch close to 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.

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

Comfort Equipment 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 room temperature. When it’s cold, confirm it’s higher. This sounds silly, but we’ve seen it occur 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 secure on your furnace cabinet or air handler. A loose panel can activate the safety switch, diverting current 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 Flickering

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

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

If this phrase or the icon is pulsing, your thermostat is in a five-minute delay state. This feature protects your equipment from harmful short cycling. This could take place 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 help.
  • 168—Wi-Fi radio error. Contact 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 take place.
  • 173—Thermostat temperature sensor error. Reach Lyric technical support at 800-633-3991.
  • 175—AC power restarted. No action needed.
  • 181/182—Install a new air filter. Clear the monitor by touching “dismiss” after installing a fresh filter.
  • 184—Put in a new humidifier pad. Clear the screen by tapping “dismiss” after installing a new pad filter.
  • 185—Put in a new dehumidifier filter. Clear the screen by tapping “dismiss” after adding a clean filter.
  • 187—Wash or put in a new ventilator filter. Clear the thermostat by hitting “dismiss” after adding a clean filter.
  • 188/189—Replace UV bulb. Ring Service Experts Heating & Air Conditioning at 239-908-6991 for help.
  • 210—Register online for exterior temperature. Download the Lyric app to do this step and ensure proper thermostat operation.
  • 388—Register online for remote access and outside temperature. Get the Lyric app to do 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 link your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump requires service. Reach Service Experts Heating & Air Conditioning at 239-908-6991 for support.
  • 168—Wi-Fi radio error. Call Service Experts Heating & Air Conditioning at 239-908-6991 for assistance.
  • 170—Internal memory error. Reach Service Experts Heating & Air Conditioning at 239-908-6991 for help.
  • 171—Set date and time. Complete these settings so scheduling can run.
  • 173—Thermostat temperature sensor error. Contact 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 support.
  • 181/182—Get a new air filter. Clear the monitor by touching “dismiss” after putting in a new filter.
  • 183—Clean humidifier tank and install a new water filter. Clear the monitor by hitting “dismiss” after doing these steps.
  • 184—Get a new humidifier pad. Clear the thermostat by touching “dismiss” after adding a new pad filter.
  • 185—Replace dehumidifier filter. Clear the thermostat by tapping “dismiss” after putting in a fresh filter.
  • 186—Clean ventilator core. Clear the thermostat by tapping “dismiss” after completing this task.
  • 187—Clean or install a new ventilator filter. Clear the monitor by touching “dismiss” after buying 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. Use the Lyric app to finish 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 pick new Wi-Fi network.
  • 508—Wi-Fi not configured. Use 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 working through the troubleshooting process, our pros are here to assist you. Call us at 239-908-6991 and we’ll arrive rapidly to determine the malfunction.

If you use an older thermostat, now is a fantastic time to think about a new thermostat. Thermostat technology has advanced in recent years Ask us for more info on how smart thermostats can make your home more comfortable while helping save on energy costs all year.

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