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 sturdy and reliable. Also, Honeywell is constantly updating its technology, bringing more features for your residence.

However, every thermostat can experience troubles now and again. That’s why we’ve prepared this valuable guide to run through troubleshooting.

While you can typically repair most thermostat troubles by yourself, they occasionally need Expert help. Our heating and cooling Experts are ready to support 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 kind of thermostat your home 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 saving on energy expenses.
  • Programmable—This thermostat includes a digital screen and arrows you use to choose your desired temperature. You can also use daily programs to decrease the temperature when you’re away and raise it when you return.
  • Smart—You won’t have to schedule any programs on this thermostat, since it adjusts to 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 raise or lower the temperature anywhere on your phone or other Wi-Fi-enabled device. 

As is the case with the majority of technologically advanced products, there are regular problems that may occur. Most of these problems don’t require Expert assistance and are simple to solve on your own.

Common Honeywell Thermostat Problems

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

Think how easy it can be to restore a computer by restarting it. In many instances, diagnosing a thermostat can be just as easy.

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

Display is Blank

If the monitor is blank on your programmable thermostat, you might need to replace the batteries. If that doesn’t take care of the problem or you rely on a smart thermostat, there could be a wiring issue.

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

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

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

Less frequently, an empty display could signify you will need to install a new thermostat.

HVAC System Won’t Turn On

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

During warm weather, confirm you schedule the thermostat beneath the room temperature. In the winter, confirm it’s higher. This sounds goofy, but we’ve seen it happen lots of times.

Ensure the power switch by your indoor equipment 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 system.

System still won’t turn on? Make sure circuit breakers haven’t tripped and that your HVAC unit 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 turn on. This is typically 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 state. This setting keeps your unit from damaging short cycling. This can occur if your power is interrupted.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump requires service. Call Climate Control Service Experts at 251-202-7503 for support.
  • 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. Contact Lyric technical support at 800-633-3991.
  • 175—AC power restored. No action necessary.
  • 181/182—Put in a new air filter. Clear the monitor by touching “dismiss” after adding a clean filter.
  • 184—Replace humidifier pad. Clear the display by touching “dismiss” after installing a clean pad filter.
  • 185—Put in a new dehumidifier filter. Clear the display by touching “dismiss” after adding a clean filter.
  • 187—Wash or install a new ventilator filter. Clear the monitor by hitting “dismiss” after putting in a clean filter.
  • 188/189—Install a new UV bulb. Call 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 accurate thermostat operation.
  • 388—Register online for remote access and outside temperature. Use the Lyric app to finish 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 set up. Use the Lyric app and follow the process to link your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump must be serviced service. Reach Climate Control Service Experts at 251-202-7503 for assistance.
  • 168—Wi-Fi radio error. Reach Climate Control Service Experts at 251-202-7503 for support.
  • 170—Internal memory error. Contact 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 help.
  • 175—AC power resumed. No action needed.
  • 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 hitting “dismiss” after putting in a new filter.
  • 183—Clean humidifier tank and add a new water filter. Clear the monitor by tapping “dismiss” after completing these tasks.
  • 184—Install a new humidifier pad. Clear the display by hitting “dismiss” after getting a new pad filter.
  • 185—Replace dehumidifier filter. Clear the display by tapping “dismiss” after adding a fresh filter.
  • 186—Wash ventilator core. Clear the monitor by hitting “dismiss” after completing this task.
  • 187—Rinse or replace ventilator filter. Clear the display by tapping “dismiss” after installing a new filter.
  • 188/189—Replace UV bulb. Get in touch with Climate Control Service Experts at 251-202-7503 for help.
  • 210—Register online for outdoor temperature. Download the Lyric app to complete this step and ensure accurate thermostat operation.
  • 388—Register online for remote access and exterior temperature. Get 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 pick new Wi-Fi network.
  • 508—Wi-Fi not connected. Download the Lyric app and follow the process to connect your thermostat.

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

Our Experts are Ready to Provide Support

If you’re still running into troubles after trying the troubleshooting steps, our Experts are available to support you. Call us at 251-202-7503 and we’ll be out as fast as we can to determine the issue.

If you use a dated thermostat, today is a fantastic time to consider a new device. Thermostat technology has come a long way in recent years Ask us for more details 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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