How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the leading thermostat manufacturers, and we proudly install them on a frequent basis in Ocala. They’re durable and reliable. In addition, Honeywell is regularly advancing its technology, bringing more features for your family.

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

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

Let’s begin the process by finding out 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 experience error codes with this kind, but it’s also the least efficient for lowering utility expenses.
  • Programmable—This thermostat features a digital screen and arrows you touch 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 make any programs on this thermostat, since it picks up on your day. It automatically adjusts the temperature when you or loved ones are out and about to help you save on energy bills. You can also change the temperature anywhere using your phone or other Wi-Fi-enabled device. 

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

Common Honeywell Thermostat Troubles

All thermostats have a special group of codes assigned to the issues that occur.

Think how easy it can be to restore 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 problems. These are applicable to the following programmable thermostats:

Display is Blank

If the monitor is clear on your programmable thermostat, you could need to install new batteries. If that doesn’t take care of the malfunction or you rely on a smart thermostat, there could 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 tightly in place.

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

Infrequently, a blank monitor could signify you will need to replace your 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 schedule the thermostat lower than the room temperature. When it’s cool, make sure it’s higher. This sounds absurd, 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 closed on your furnace cabinet or air handler. An open panel can trip the safety switch, cutting off electricity to the unit.

Equipment still won’t start? 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 switched to “cool” or “heat.”

Then, ensure it’s telling the right equipment to start. This is typically indicated by “cool on,” “heat on” or a picture.

If this phrase or the illustration is blinking, your thermostat is in a five-minute delay state. This setting protects your equipment from damaging 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 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. Contact 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—Put in 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—Put in a new dehumidifier filter. Clear the display by tapping “dismiss” after installing a fresh filter.
  • 187—Clean or install a new ventilator filter. Clear the monitor by tapping “dismiss” after adding a fresh 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 finish this step and ensure accurate thermostat operation.
  • 388—Register online for remote access and outside temperature. Use the Lyric app to do this step and ensure proper 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. 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 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 support.
  • 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 operate.
  • 173—Thermostat temperature sensor error. Reach Service Experts Heating & Air Conditioning at 352-414-4006 for assistance.
  • 175—AC power reconnected. No action needed.
  • 177—Indoor temperature sensor error. Contact 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 support.
  • 181/182—Install a new air filter. Clear the thermostat by hitting “dismiss” after adding a new filter.
  • 183—Clean humidifier tank and replace water filter. Clear the screen by tapping “dismiss” after completing these procedures.
  • 184—Replace humidifier pad. Clear the thermostat by hitting “dismiss” after installing pad filter.
  • 185—Replace dehumidifier filter. Clear the display by touching “dismiss” after putting in a clean filter.
  • 186—Clean ventilator core. Clear the thermostat by touching “dismiss” after doing this task.
  • 187—Rinse or replace ventilator filter. Clear the monitor by touching “dismiss” after installing a new filter.
  • 188/189—Install a new UV bulb. Get in touch with Service Experts Heating & Air Conditioning at 352-414-4006 for support.
  • 210—Register online for outdoor 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 complete this step and ensure correct 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 connected. 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 Ready to Provide Support

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

If you use an older thermostat, today is a fantastic time to think about 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 utility bills year-round.

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