How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the leading thermostat producers, and we proudly install them on a frequent basis in Atlanta. They’re durable and dependable. In addition, Honeywell is constantly updating its technology, resulting in more features for your house.

Still, each thermostat can have errors at one time or another. As a result, we’ve prepared this useful guide to go over troubleshooting.

While you can usually repair many thermostat troubles on your own, they often require Expert support. Our heating and cooling pros are available to assist you when you need us. We’re merely a call away at 678-235-9699.

Let’s get started with the process by finding 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 kind, but it’s also the least efficient for saving on heating and cooling costs.
  • Programmable—This thermostat has a digital screen and arrows you touch to choose your desired temperature. You can also use daily programs to reduce the temperature when you’re at work and set it higher when you come home.
  • Smart—You won’t have to schedule any programs on this thermostat, because it learns your day. It instinctively adjusts the temperature when you or loved ones are gone to help you save on utility bills. You can also raise or lower the temperature anywhere on your phone or other Wi-Fi-enabled device. 

As you know the majority of technologically advanced things, there are common problems that might occur. Most of these troubles don’t call for pro assistance and are uncomplicated enough to repair on your own.

Common Honeywell Thermostat Issues

Each thermostat has an exclusive kind of codes matching the problems that happen.

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

Here is a guide to the most common Honeywell thermostat problems. These apply to the following programmable thermostats:

Display is Blank

If the monitor is blank on your programmable thermostat, you may need to get new batteries. If that doesn’t fix the problem or you have a smart thermostat, there could be a wiring malfunction.

Next, you should make sure the power is flowing for your furnace or air handler. Confirm the switch close to the indoor unit is switched “up”.

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

An unsecured panel may activate the safety switch, which cuts off power to the unit.

Less frequently, an empty screen may indicate you should buy a new thermostat.

Comfort Unit Won’t Run

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

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

Confirm the power switch close to your indoor unit is in the “on” position. You should also comfirm the cabinet doors or panels are closed on your furnace cabinet or air handler. An open panel can trigger the safety switch, cutting off electricity to the system.

Heating or cooling still won’t start? Make sure circuit breakers haven’t tripped and that your HVAC unit isn’t showing error codes.

“Cool On” or “Heat On” is Blinking

First, make sure your thermostat is switched to “cool” or “heat.”

Then, check it’s signaling the appropriate equipment to turn on. This is often indicated by “cool on,” “heat on” or an icon.

If these words or the illustration is pulsing, your thermostat is in a five-minute delay status. This mode keeps your system from bad short cycling. This can take place if your power is interrupted.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump must be serviced. Call Peachtree Service Experts at 678-235-9699 for help.
  • 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 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 screen by touching “dismiss” after installing a new filter.
  • 184—Put in a new humidifier pad. Clear the thermostat by hitting “dismiss” after adding a new pad filter.
  • 185—Replace dehumidifier filter. Clear the thermostat by hitting “dismiss” after putting in a new filter.
  • 187—Wash or replace ventilator filter. Clear the monitor by tapping “dismiss” after putting in a clean filter.
  • 188/189—Install a new UV bulb. Contact Peachtree Service Experts at 678-235-9699 for help.
  • 210—Register online for outside temperature. Use the Lyric app to complete this step and ensure accurate thermostat operation.
  • 388—Register online for remote access and outdoor temperature. Use the Lyric app to complete this step and ensure correct 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 set up. Download 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 Peachtree Service Experts at 678-235-9699 for help.
  • 168—Wi-Fi radio error. Reach Peachtree Service Experts at 678-235-9699 for help.
  • 170—Internal memory error. Contact Peachtree Service Experts at 678-235-9699 for help.
  • 171—Set date and time. Finish these settings so scheduling can work.
  • 173—Thermostat temperature sensor error. Call Peachtree Service Experts at 678-235-9699 for support.
  • 175—AC power restored. No action required.
  • 177—Indoor temperature sensor error. Contact Peachtree Service Experts at 678-235-9699 for help.
  • 178—Outdoor temperature sensor error. Call Peachtree Service Experts at 678-235-9699 for help.
  • 181/182—Replace air filter. Clear the screen by touching “dismiss” after putting in a new filter.
  • 183—Rinse humidifier tank and add a new water filter. Clear the screen by hitting “dismiss” after finishing these procedures.
  • 184—Install a new humidifier pad. Clear the display by tapping “dismiss” after adding a new pad filter.
  • 185—Get a new dehumidifier filter. Clear the thermostat by tapping “dismiss” after putting in a new filter.
  • 186—Wash ventilator core. Clear the monitor by hitting “dismiss” after doing this task.
  • 187—Wash or install a new ventilator filter. Clear the display by touching “dismiss” after installing a new filter.
  • 188/189—Install a new UV bulb. Reach Peachtree Service Experts at 678-235-9699 for support.
  • 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. 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 procedures to connect your thermostat.

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

Our Experts are Available to Provide Assistance

If you’re still running into problems after trying the troubleshooting steps, our pros are available to help. Give us a call at 678-235-9699 and we’ll come to your house rapidly to diagnose the malfunction.

If you rely on a dated thermostat, right now is a great time to consider a replacement. Thermostat technology has advanced lately Ask us for more details on how smart thermostats can make your residence comfier while helping save on energy expenses year-round.

Contact Us