How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the top thermostat manufacturers, and we proudly install them on a regular basis in Hilton Head Island. They’re sturdy and trustworthy. Plus, Honeywell is constantly improving its technology, bringing more features for your family.

However, all thermostats can have problems once in awhile. As a result, we’ve put together this valuable manual to go over troubleshooting.

While you can typically repair the majority of thermostat issues alone, they occasionally call for Expert help. Our heating and cooling professionals are ready to help when you need us. We’re just a call away at 843-619-3781.

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

What Model of Thermostat Do I Have?

There are three types of thermostats:

  • Manual—This is the older dial-shaped thermostat. You won’t run into error codes with this type, but it’s also the least efficient for saving on utility expenses.
  • Programmable—This thermostat features a digital screen and arrows you touch to choose your desired temperature. You can also choose daily programs to lower the temperature when you’re at work and raise it when you return.
  • Smart—You won’t have to make any programs on this thermostat, since it learns your routine. It intuitively raises and lowers the temperature when you or family members are away to help you save on utility bills. You can also adjust the temperature anywhere via your phone or other Wi-Fi-enabled device. 

As you’re aware the majority of technologically advanced solutions, there are common glitches that can take place. Most of these problems don’t call for pro help and are simple to repair alone.

Common Honeywell Thermostat Troubles

Each thermostat has a unique kind of codes assigned to the problems that occur.

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

Here are some of the most common Honeywell thermostat issues. These involve the following programmable thermostats:

Display is Blank

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

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

In addition to that, you should confirm all furnace cabinet or air handler doors/panels are securely secured.

An unsecured panel may trip the safety switch, which stops power to the system.

While it’s less common, a clear monitor may indicate you will need to get a new thermostat.

Comfort Equipment Won’t Start

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

During warm weather, make sure you set the thermostat beneath the room temperature. When it’s cool, confirm it’s higher. This sounds silly, but we’ve seen it occur lots of times.

Ensure the power switch by your indoor unit is in the “on” position. You should also comfirm the cabinet doors or panels are secure on your furnace cabinet or air handler. An unsecured panel can trigger the safety switch, cutting off current to the system.

Heating or cooling still won’t run? Confirm circuit breakers haven’t turned off and that your HVAC system isn’t displaying error codes.

“Cool On” or “Heat On” is Flickering

To start, confirm your thermostat is switched to “cool” or “heat.”

Then, ensure it’s calling for the right system to turn on. This is typically shown by “cool on,” “heat on” or an illustration.

If this phrase or the picture is pulsing, your thermostat is in a five-minute delay state. This setting protects your equipment from bad short cycling. This could take place if your power is interrupted.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump needs service. Call Epperson Service Experts at 843-619-3781 for assistance.
  • 168—Wi-Fi radio error. Reach Lyric technical support at 800-633-3991. 170—Internal memory error. Reach Lyric technical support at 800-633-3991.
  • 171—Set date and time. Finalize these settings so scheduling can occur.
  • 173—Thermostat temperature sensor error. Reach Lyric technical support at 800-633-3991.
  • 175—AC power resumed. No action required.
  • 181/182—Install a new air filter. Clear the screen by hitting “dismiss” after installing a fresh filter.
  • 184—Install a new humidifier pad. Clear the thermostat by tapping “dismiss” after adding a fresh pad filter.
  • 185—Replace dehumidifier filter. Clear the thermostat by tapping “dismiss” after adding a new filter.
  • 187—Wash or install a new ventilator filter. Clear the screen by touching “dismiss” after adding a new filter.
  • 188/189—Get a new UV bulb. Ring Epperson Service Experts at 843-619-3781 for help.
  • 210—Register online for outside temperature. Download the Lyric app to complete this step and ensure proper thermostat operation.
  • 388—Register online for remote access and exterior temperature. Download the Lyric app to do this step and ensure accurate thermostat operation.
  • 399—No Internet. Confirm 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. Use the Lyric app and follow the procedure to configure your thermostat.

For more specifics, view this thermostat’s user manual.

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump needs service. Call Epperson Service Experts at 843-619-3781 for help.
  • 168—Wi-Fi radio error. Contact Epperson Service Experts at 843-619-3781 for support.
  • 170—Internal memory error. Reach Epperson Service Experts at 843-619-3781 for assistance.
  • 171—Set date and time. Complete these settings so scheduling can run.
  • 173—Thermostat temperature sensor error. Contact Epperson Service Experts at 843-619-3781 for support.
  • 175—AC power reconnected. No action required.
  • 177—Indoor temperature sensor error. Contact Epperson Service Experts at 843-619-3781 for support.
  • 178—Outdoor temperature sensor error. Contact Epperson Service Experts at 843-619-3781 for support.
  • 181/182—Replace air filter. Clear the screen by tapping “dismiss” after putting in a clean filter.
  • 183—Clean humidifier tank and install a new water filter. Clear the monitor by tapping “dismiss” after finishing these procedures.
  • 184—Install a new humidifier pad. Clear the thermostat by tapping “dismiss” after adding a new pad filter.
  • 185—Replace dehumidifier filter. Clear the display by touching “dismiss” after installing a clean filter.
  • 186—Clean ventilator core. Clear the monitor by touching “dismiss” after finishing this task.
  • 187—Wash or replace ventilator filter. Clear the screen by hitting “dismiss” after installing a new filter.
  • 188/189—Add a new UV bulb. Get in touch with Epperson Service Experts at 843-619-3781 for assistance.
  • 210—Register online for outside temperature. Get the Lyric app to do this step and ensure accurate thermostat operation.
  • 388—Register online for remote access and outdoor temperature. Download the Lyric app to complete this step and ensure proper thermostat operation.
  • 399—No Internet. Check 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. Download the Lyric app and follow the process to connect your thermostat.

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

Our Experts are Here to Help

If you’re still experiencing problems after going through the troubleshooting steps, our Experts are here to assist you. Call us at 843-619-3781 and we’ll be out quickly to figure out the issue.

If you use a dated thermostat, now is a fantastic time to think about a new device. Thermostat technology has come a long way lately Ask us for more info on how smart thermostats can make your residence better while helping save on utility expenses year-round.

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