How to Troubleshoot Honeywell Thermostat Errors

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

However, all thermostats can have problems at one time or another. As a result, we’ve compiled this valuable manual to run through troubleshooting.

While you can often repair the majority of thermostat issues by yourself, 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 kind of thermostat your home has.

What Type of Thermostat Do I Have?

There are three types of thermostats:

  • Manual—This is the typical 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 includes a digital screen and arrows you use to determine your desired temperature. You can also choose daily programs to lower the temperature when you’re at work and raise it when you get back.
  • Smart—You won’t have to make any programs on this thermostat, since it learns your day. It intuitively changes the temperature when you or loved ones 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 things, there are common malfunctions that can take place. The majority of of these problems don’t need Expert support and are simple to repair by yourself.

Common Honeywell Thermostat Troubles

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

Think how simple it can be to fix a computer by restarting it. In many instances, diagnosing 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 screen is empty on your programmable thermostat, you could need to put in new batteries. If that doesn’t take care of the issue or you rely on a smart thermostat, there might be a wiring malfunction.

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

Also, 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.

Less frequently, an empty screen may indicate you will need to get a new thermostat.

Heating and Cooling Equipment Won’t Start

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

When it’s hot, make sure you set the thermostat below the ambient temperature. When it’s cold, verify it’s higher. This sounds silly, but we’ve seen it take place 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 activate the safety switch, cutting off electricity to the equipment.

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

“Cool On” or “Heat On” is Flickering

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

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

If this phrase or the picture is blinking, your thermostat is in a five-minute delay state. This feature protects your unit 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. 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. Finalize these settings so scheduling can occur.
  • 173—Thermostat temperature sensor error. Contact 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 tapping “dismiss” after installing a fresh filter.
  • 184—Install a new humidifier pad. Clear the thermostat by hitting “dismiss” after putting in a fresh pad filter.
  • 185—Replace dehumidifier filter. Clear the thermostat by hitting “dismiss” after adding a new filter.
  • 187—Wash or put in a new ventilator filter. Clear the screen by touching “dismiss” after putting in a new filter.
  • 188/189—Get a new UV bulb. Call Epperson Service Experts at 843-619-3781 for support.
  • 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 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 select new Wi-Fi network.
  • 508—Wi-Fi not set. Get the Lyric app and follow the process to link your thermostat.

For more details, 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 support.
  • 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 help.
  • 175—AC power restored. No action required.
  • 177—Indoor temperature sensor error. Contact Epperson Service Experts at 843-619-3781 for help.
  • 178—Outdoor temperature sensor error. Contact Epperson Service Experts at 843-619-3781 for help.
  • 181/182—Replace air filter. Clear the monitor by hitting “dismiss” after adding a clean filter.
  • 183—Clean humidifier tank and add a new water filter. Clear the monitor by tapping “dismiss” after doing these steps.
  • 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 fresh 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. Reach Epperson Service Experts at 843-619-3781 for assistance.
  • 210—Register online for outside temperature. Use the Lyric app to finish 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 choose new Wi-Fi network.
  • 508—Wi-Fi not configured. Download the Lyric app and follow the process to connect your thermostat.

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

Our Experts are Here to Help

If you’re still running into problems after trying the troubleshooting steps, our Experts are here to support you. Reach us at 843-619-3781 and we’ll be out quickly to figure out the malfunction.

If you rely on an aging thermostat, now is a great time to think over a new thermostat. Thermostat technology has come a long way in recent years Ask us for more details on how smart thermostats can make your house better while helping save on utility expenses year-round.

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