How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the best thermostat brands, and we proudly install them on a regular basis in Albany. They’re sturdy and reliable. In addition, Honeywell is regularly advancing its technology, offering more features for your home.

Nevertheless, all thermostats can run into troubles now and again. That’s why we’ve put together this valuable handbook to go over troubleshooting. While Honeywell thermostat problems are rare, they happen. 

While you can usually solve most thermostat problems alone, they occasionally require Expert help. Our HVAC professionals are here to support you when you need us. We’re merely a call away at 518-417-2938.

Let’s start the process by finding out what model of thermostat your house has.

What Kind of Thermostat Do I Have?

There are three models of thermostats:

  • Manual—This is the typical dial-shaped thermostat. You won’t experience error codes with this one, but it’s also the least efficient for reducing energy bills.
  • Programmable—This thermostat includes a digital screen and arrows you touch to determine your desired temperature. You can also choose daily programs to reduce the temperature when you’re gone and set it higher when you get back.
  • Smart—You won’t have to make any programs on this thermostat, since it learns your day. It automatically adjusts the temperature when you or family members are away to help you save on utility bills. You can also raise or lower the temperature anywhere using your phone or other Wi-Fi-enabled device. 

As is the case with many technologically advanced solutions, there are common glitches that may occur. Most of these troubles don’t need Expert assistance and are uncomplicated enough to fix by yourself.

Common Honeywell Thermostat Problems

Every thermostat has an exclusive kind of codes matching the troubles that happen.

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

Here is a listing the most reported Honeywell thermostat problems. These involve the following programmable thermostats:

Display is Blank

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

Next, you should check the power is flowing for your furnace or air handler. Confirm the switch by the indoor system is switched “up”.

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

A panel that isn’t tight may trigger the safety switch, which stops power to the equipment.

Less frequently, a blank display might mean you need to install a new thermostat.

Comfort Equipment Won’t Turn On

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

When it’s hot, confirm you schedule the thermostat below the current temperature. When it’s cool, make sure it’s higher. This sounds absurd, but we’ve seen it happen many 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 tight on your furnace cabinet or air handler. An open panel can trip the safety switch, diverting power to the system.

Heating or cooling still won’t turn on? Confirm circuit breakers haven’t turned off and that your HVAC unit isn’t displaying error codes.

“Cool On” or “Heat On” is Flashing

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

Then, check it’s telling the correct system to turn on. This is usually shown by “cool on,” “heat on” or a picture.

If these words or the illustration is pulsing, your thermostat is in a five-minute delay mode. This mode stops your system from damaging short cycling. This could take place if you lose power.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump requires service. Call Roland J. Down Service Experts at 518-417-2938 for help.
  • 168—Wi-Fi radio error. Call Lyric technical support at 800-633-3991. 170—Internal memory error. Contact Lyric technical support at 800-633-3991.
  • 171—Set date and time. Complete 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 necessary.
  • 181/182—Put in a new air filter. Clear the thermostat by tapping “dismiss” after adding a fresh filter.
  • 184—Replace humidifier pad. Clear the monitor by touching “dismiss” after adding a fresh pad filter.
  • 185—Replace dehumidifier filter. Clear the monitor by hitting “dismiss” after putting in a fresh filter.
  • 187—Rinse or install a new ventilator filter. Clear the monitor by tapping “dismiss” after adding a fresh filter.
  • 188/189—Replace UV bulb. Ring Roland J. Down Service Experts at 518-417-2938 for support.
  • 210—Register online for exterior temperature. Use the Lyric app to finish this step and ensure accurate thermostat operation.
  • 388—Register online for remote access and outdoor temperature. Get the Lyric app to do 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 set. Download the Lyric app and follow the procedure 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 Roland J. Down Service Experts at 518-417-2938 for assistance.
  • 168—Wi-Fi radio error. Reach Roland J. Down Service Experts at 518-417-2938 for help.
  • 170—Internal memory error. Contact Roland J. Down Service Experts at 518-417-2938 for assistance.
  • 171—Set date and time. Complete these settings so scheduling can operate.
  • 173—Thermostat temperature sensor error. Contact Roland J. Down Service Experts at 518-417-2938 for assistance.
  • 175—AC power reconnected. No action needed.
  • 177—Indoor temperature sensor error. Contact Roland J. Down Service Experts at 518-417-2938 for help.
  • 178—Outdoor temperature sensor error. Contact Roland J. Down Service Experts at 518-417-2938 for assistance.
  • 181/182—Install a new air filter. Clear the monitor by tapping “dismiss” after adding a new filter.
  • 183—Wash humidifier tank and replace water filter. Clear the monitor by hitting “dismiss” after completing these tasks.
  • 184—Replace humidifier pad. Clear the thermostat by hitting “dismiss” after getting a new pad filter.
  • 185—Install a new dehumidifier filter. Clear the thermostat by tapping “dismiss” after putting in a clean filter.
  • 186—Rinse ventilator core. Clear the display by touching “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. Get in touch with Roland J. Down Service Experts at 518-417-2938 for help.
  • 210—Register online for exterior temperature. Download the Lyric app to do this step and ensure accurate thermostat operation.
  • 388—Register online for remote access and outdoor temperature. Get 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 pick new Wi-Fi network.
  • 508—Wi-Fi not set up. Download the Lyric app and follow the procedures to connect your thermostat.

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

Our Experts are Here to Provide Support

If you’re still experiencing problems after working through the troubleshooting steps, our professionals are here to support you. Call us at 518-417-2938 and we’ll be out as fast as we can to determine the issue.

If you rely on an older thermostat, now is a great time to think about a new thermostat. Thermostat technology has advanced over the last few years. Ask us for more info on how smart thermostats can make your residence better while helping save on heating and cooling bills year-round.

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