How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the leading thermostat brands, and we proudly install them on a regular basis in Jacksonville. They’re durable and trustworthy. Also, Honeywell is constantly enhancing its technology, offering more features for your family.

Still, all thermostats can have problems every so often. As a result, we’ve put together this helpful guide to go over troubleshooting.

While you can usually fix many thermostat troubles on your own, they occasionally require Expert support. Our heating and cooling professionals are ready to assist you when you need us. We’re just a call away at 904-450-5672.

Let’s start the process by figuring out what kind of thermostat your house has.

What Kind of Thermostat Do I Have?

There are three types of thermostats:

  • Manual—This is the typical dial-shaped thermostat. You won’t have error codes with this one, but it’s also the least efficient for lowering energy costs.
  • Programmable—This thermostat features a digital screen and arrows you use to determine your desired temperature. You can also set daily programs to decrease the temperature when you’re away and set it higher when you return.
  • Smart—You won’t have to make any programs on this thermostat, since it learns your schedule. It instinctively adjusts the temperature when you or family members are out and about to help you save on energy bills. You can also adjust the temperature anywhere on your phone or other Wi-Fi-enabled device. 

As you’re aware most technologically advanced products, there are several glitches that may happen. Many of these troubles don’t need Expert help and are uncomplicated enough to repair by yourself.

Common Honeywell Thermostat Problems

All thermostats have an exclusive set of codes matching the glitches that take place.

Think how uncomplicated it can be to restore a computer by restarting it. In most cases, diagnosing a thermostat can be just as simple.

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

Display is Blank

If the display is clear on your programmable thermostat, you may need to install new batteries. If that doesn’t solve the problem or you use a smart thermostat, there may be a wiring issue.

Next, you should make sure the power is enabled for your furnace or air handler. Make sure the switch by the indoor unit is switched “up”.

In addition to that, you should make certain all furnace cabinet or air handler doors/panels are sturdily fastened.

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

While it’s less common, a clear monitor might mean you should get a new thermostat.

Heating and Cooling Equipment Won’t Work

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

In the summer, make sure you schedule the thermostat below the room temperature. In the winter, verify it’s higher. This sounds absurd, but we’ve seen it occur lots of times.

Confirm the power switch by your indoor equipment is in the “on” position. You should also make sure the cabinet doors or panels are secure on your furnace cabinet or air handler. An unsecured panel can activate the safety switch, diverting electricity to the system.

Equipment still won’t turn on? Verify circuit breakers haven’t turned off and that your HVAC equipment isn’t displaying error codes.

“Cool On” or “Heat On” is Blinking

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

Then, verify it’s calling for the correct equipment to run. This is often demonstrated by “cool on,” “heat on” or a picture.

If these words or the icon is pulsing, your thermostat is in a five-minute delay status. This setting protects your system from bad short cycling. This may take place if you lose electricity.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump requires service. Call Air Engineers Service Experts at 904-450-5672 for assistance.
  • 168—Wi-Fi radio error. Reach 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 take place.
  • 173—Thermostat temperature sensor error. Reach Lyric technical support at 800-633-3991.
  • 175—AC power restarted. No action necessary.
  • 181/182—Put in a new air filter. Clear the thermostat by touching “dismiss” after installing a new filter.
  • 184—Put in a new humidifier pad. Clear the screen by touching “dismiss” after adding a fresh pad filter.
  • 185—Install a new dehumidifier filter. Clear the monitor by hitting “dismiss” after adding a clean filter.
  • 187—Wash or install a new ventilator filter. Clear the screen by touching “dismiss” after installing a new filter.
  • 188/189—Get a new UV bulb. Contact Air Engineers Service Experts at 904-450-5672 for help.
  • 210—Register online for exterior temperature. Get the Lyric app to finish 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 accurate 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 configured. Use the Lyric app and follow the procedure to link your thermostat.

For more details, look at this thermostat’s user manual.

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump needs service. Contact Air Engineers Service Experts at 904-450-5672 for assistance.
  • 168—Wi-Fi radio error. Contact Air Engineers Service Experts at 904-450-5672 for support.
  • 170—Internal memory error. Contact Air Engineers Service Experts at 904-450-5672 for support.
  • 171—Set date and time. Finalize these settings so scheduling can run.
  • 173—Thermostat temperature sensor error. Reach Air Engineers Service Experts at 904-450-5672 for help.
  • 175—AC power resumed. No action necessary.
  • 177—Indoor temperature sensor error. Call Air Engineers Service Experts at 904-450-5672 for support.
  • 178—Outdoor temperature sensor error. Reach Air Engineers Service Experts at 904-450-5672 for help.
  • 181/182—Install a new air filter. Clear the monitor by hitting “dismiss” after putting in a fresh filter.
  • 183—Clean humidifier tank and replace water filter. Clear the monitor by tapping “dismiss” after completing these procedures.
  • 184—Replace humidifier pad. Clear the screen by touching “dismiss” after installing pad filter.
  • 185—Install a new dehumidifier filter. Clear the monitor by hitting “dismiss” after adding a new filter.
  • 186—Wash ventilator core. Clear the display by touching “dismiss” after finishing this task.
  • 187—Rinse or install a new ventilator filter. Clear the display by touching “dismiss” after buying a new filter.
  • 188/189—Get a new UV bulb. Contact Air Engineers Service Experts at 904-450-5672 for support.
  • 210—Register online for outdoor temperature. Get the Lyric app to complete this step and ensure correct thermostat operation.
  • 388—Register online for remote access and outdoor temperature. Get the Lyric app to finish this step and ensure proper 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. Download the Lyric app and follow the process to connect your thermostat.

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

Our Experts are Here to Provide Assistance

If you’re still running into troubles after working through the troubleshooting steps, our Experts are available to support you. Give us a call at 904-450-5672 and we’ll arrive quickly to determine the malfunction.

If you have an older thermostat, now is a good time to consider a new thermostat. Thermostat technology has gotten better lately Ask us for more information on how smart thermostats can make your residence better while helping save on energy expenses throughout the year.

Contact Us