How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the best thermostat manufacturers, and we proudly install them on a regular basis in Mobile. They’re long-lasting and dependable. Also, Honeywell is constantly updating its technology, bringing more features for your residence.

However, every thermostat can run into troubles every so often. That’s why we’ve prepared this valuable manual to run through troubleshooting. While Honeywell thermostat problems are rare, they happen. 

While you can often solve most thermostat issues by yourself, they occasionally need Expert support. Our heating and cooling professionals are ready to assist you when you need us. We’re only a call away at 251-202-7503.

Let’s get started with the process by figuring out what model of thermostat your home has.

What Type of Thermostat Do I Have?

There are three models of thermostats:

  • Manual—This is the typical dial-shaped thermostat. You won’t have 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 use to determine your desired temperature. You can also choose daily programs to lower the temperature when you’re away and raise it when you get back.
  • Smart—You won’t have to make any programs on this thermostat, since it picks up on your schedule. It instinctively adjusts the temperature when you or other household members are away to help you save on heating and cooling bills. You can also change the temperature anywhere on your phone or other Wi-Fi-enabled device. 

As is the case with many technologically advanced products, there are several problems that may occur. Most of these problems don’t require pro assistance and are simple to repair on your own.

Common Honeywell Thermostat Problems

Each thermostat has an exclusive set of codes assigned to the issues that take place.

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

Here are some of the most encountered Honeywell thermostat errors. These include the following programmable thermostats:

Display is Blank

If the screen is blank on your programmable thermostat, you might need to get new batteries. If that doesn’t take care of the problem or you use a smart thermostat, there may be a wiring issue.

Next, you should check the power is enabled for your furnace or air handler. Verify the switch by the indoor system is in the “on” position.

Also, you should make certain all furnace cabinet or air handler doors/panels are sturdily fastened.

A loose panel may activate the safety switch, which cuts off power to the unit.

While it’s less common, an empty display could signify you will need to install a new thermostat.

HVAC System Won’t Run

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

When it’s hot, verify you put the thermostat below the room temperature. In the winter, confirm it’s higher. This sounds goofy, but we’ve seen it happen a lot of times.

Ensure the power switch by your indoor system is in the “on” position. You should also make sure the cabinet doors or panels are closed on your furnace cabinet or air handler. A loose panel can activate the safety switch, cutting off power to the equipment.

Unit still won’t turn on? Make sure circuit breakers haven’t tripped and that your HVAC equipment isn’t displaying error codes.

“Cool On” or “Heat On” is Flashing

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

Then, make sure it’s signaling the appropriate unit to start. This is often shown by “cool on,” “heat on” or an illustration.

If this set of words or the icon is flashing, your thermostat is in a five-minute delay status. This setting keeps your equipment from damaging short cycling. This can take place if you lose electricity.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump needs service. Call Climate Control Service Experts at 251-202-7503 for help.
  • 168—Wi-Fi radio error. Call Lyric technical support at 800-633-3991. 170—Internal memory error. Call 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 restored. No action needed.
  • 181/182—Put in a new air filter. Clear the monitor by touching “dismiss” after putting in a clean filter.
  • 184—Replace humidifier pad. Clear the display by touching “dismiss” after installing a fresh pad filter.
  • 185—Put in a new dehumidifier filter. Clear the display by touching “dismiss” after adding a fresh filter.
  • 187—Wash or put in a new ventilator filter. Clear the monitor by tapping “dismiss” after adding a clean filter.
  • 188/189—Install a new UV bulb. Ring Climate Control Service Experts at 251-202-7503 for help.
  • 210—Register online for outdoor temperature. Use the Lyric app to complete this step and ensure correct thermostat operation.
  • 388—Register online for remote access and exterior temperature. Get the Lyric app to finish this step and ensure correct thermostat operation.
  • 399—No Internet. Confirm your network settings.
  • 400—No Wi-Fi signal. Wait for the thermostat to reconnect or choose new Wi-Fi network.
  • 508—Wi-Fi not set. Get the Lyric app and follow the process to configure your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump requires service. Contact Climate Control Service Experts at 251-202-7503 for assistance.
  • 168—Wi-Fi radio error. Contact Climate Control Service Experts at 251-202-7503 for help.
  • 170—Internal memory error. Reach Climate Control Service Experts at 251-202-7503 for assistance.
  • 171—Set date and time. Finish these settings so scheduling can run.
  • 173—Thermostat temperature sensor error. Reach Climate Control Service Experts at 251-202-7503 for support.
  • 175—AC power resumed. No action necessary.
  • 177—Indoor temperature sensor error. Reach Climate Control Service Experts at 251-202-7503 for support.
  • 178—Outdoor temperature sensor error. Contact Climate Control Service Experts at 251-202-7503 for assistance.
  • 181/182—Replace air filter. Clear the thermostat by tapping “dismiss” after adding a new filter.
  • 183—Clean humidifier tank and install a new water filter. Clear the monitor by tapping “dismiss” after completing these tasks.
  • 184—Get a new humidifier pad. Clear the display by hitting “dismiss” after adding a new pad filter.
  • 185—Replace dehumidifier filter. Clear the display by tapping “dismiss” after putting in a fresh filter.
  • 186—Rinse ventilator core. Clear the monitor by hitting “dismiss” after finishing this task.
  • 187—Rinse or replace ventilator filter. Clear the monitor by hitting “dismiss” after installing a new filter.
  • 188/189—Replace UV bulb. Reach Climate Control Service Experts at 251-202-7503 for support.
  • 210—Register online for outdoor temperature. Download the Lyric app to complete this step and ensure correct 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 pick new Wi-Fi network.
  • 508—Wi-Fi not connected. Download the Lyric app and follow the procedures to connect your thermostat.

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

Our Experts are Available to Provide Assistance

If you’re still running into issues after trying the troubleshooting steps, our Experts are ready to support you. Reach us at 251-202-7503 and we’ll be out rapidly to figure out the malfunction.

If you use a dated thermostat, today is a great time to consider a new thermostat. Thermostat technology has come a long way lately Ask us for more info on how smart thermostats can make your residence more comfortable while helping save on heating and cooling bills throughout the year.

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