How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the leading thermostat producers, and we proudly install them on a usual basis in Shreveport. They’re long-lasting and reliable. In addition, Honeywell is regularly advancing its technology, bringing more features for your home.

Still, all thermostats can experience errors now and then. As a result, we’ve compiled this valuable handbook to go over troubleshooting. While Honeywell thermostat problems are rare, they do pop up. 

While you can typically repair most thermostat problems on your own, they occasionally require Expert help. Our home comfort Experts are here to support you when you need us. We’re merely a call away at 318-588-8163.

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

What Kind of Thermostat Do I Have?

There are three kinds of thermostats:

  • Manual—This is the classic dial-shaped thermostat. You won’t run into error codes with this one, but it’s also the least efficient for reducing heating and cooling costs.
  • Programmable—This thermostat includes 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 gone and set it higher when you return.
  • Smart—You won’t have to make any programs on this thermostat, because it adjusts to your day. It intuitively raises and lowers the temperature when you or family members are away to help you save on heating and cooling expenses. You can also change the temperature anywhere via your phone or other Wi-Fi-enabled device. 

As you’re aware many technologically advanced solutions, there are several malfunctions that might happen. Many of these troubles don’t call for Expert assistance and are simple to solve alone.

Common Honeywell Thermostat Troubles

All thermostats have a special set of codes matching the glitches that happen.

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

Here are some of the most common Honeywell thermostat errors. These involve 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 fix the problem or you rely on a smart thermostat, there may be a wiring malfunction.

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

In addition to that, you should make sure all furnace cabinet or air handler doors/panels are securely secured.

A panel that isn’t tight may activate the safety switch, which disconnects power to the system.

While it’s less common, a clear monitor can indicate you need to buy a new thermostat.

HVAC Equipment Won’t Work

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

During warm weather, verify you schedule the thermostat beneath the ambient temperature. In the winter, confirm it’s higher. This sounds silly, but we’ve seen it happen many times.

Make sure the power switch by your indoor system is in the “on” position. You should also check the cabinet doors or panels are tight on your furnace cabinet or air handler. An open panel can trip the safety switch, cutting off electricity to the equipment.

System still won’t turn on? Confirm circuit breakers haven’t tripped and that your HVAC system isn’t showing error codes.

“Cool On” or “Heat On” is Blinking

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

Then, make sure it’s telling the right system to start. This is often demonstrated by “cool on,” “heat on” or an icon.

If these words or the icon is flashing, your thermostat is in a five-minute delay status. This setting protects your system from harmful short cycling. This may happen if your power is interrupted.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump needs service. Call Service Experts Heating & Air Conditioning at 318-588-8163 for assistance.
  • 168—Wi-Fi radio error. Contact Lyric technical support at 800-633-3991. 170—Internal memory error. Contact Lyric technical support at 800-633-3991.
  • 171—Set date and time. Finish these settings so scheduling can occur.
  • 173—Thermostat temperature sensor error. Call Lyric technical support at 800-633-3991.
  • 175—AC power restored. No action needed.
  • 181/182—Replace air filter. Clear the screen by tapping “dismiss” after putting in a new filter.
  • 184—Put in a new humidifier pad. Clear the display by touching “dismiss” after adding a new pad filter.
  • 185—Install a new dehumidifier filter. Clear the monitor by touching “dismiss” after adding a clean filter.
  • 187—Clean or install a new ventilator filter. Clear the thermostat by tapping “dismiss” after installing a fresh filter.
  • 188/189—Install a new UV bulb. Ring Service Experts Heating & Air Conditioning at 318-588-8163 for assistance.
  • 210—Register online for outdoor temperature. Use the Lyric app to complete this step and ensure proper thermostat operation.
  • 388—Register online for remote access and outdoor temperature. Download the Lyric app to do 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 set up. Use the Lyric app and follow the process to link your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump needs service. Reach Service Experts Heating & Air Conditioning at 318-588-8163 for support.
  • 168—Wi-Fi radio error. Call Service Experts Heating & Air Conditioning at 318-588-8163 for support.
  • 170—Internal memory error. Call Service Experts Heating & Air Conditioning at 318-588-8163 for assistance.
  • 171—Set date and time. Complete these settings so scheduling can run.
  • 173—Thermostat temperature sensor error. Call Service Experts Heating & Air Conditioning at 318-588-8163 for assistance.
  • 175—AC power reconnected. No action necessary.
  • 177—Indoor temperature sensor error. Reach Service Experts Heating & Air Conditioning at 318-588-8163 for help.
  • 178—Outdoor temperature sensor error. Call Service Experts Heating & Air Conditioning at 318-588-8163 for support.
  • 181/182—Get a new air filter. Clear the thermostat by touching “dismiss” after adding a fresh filter.
  • 183—Clean humidifier tank and replace water filter. Clear the screen by touching “dismiss” after completing these tasks.
  • 184—Replace humidifier pad. Clear the display by hitting “dismiss” after getting a new pad filter.
  • 185—Get a new dehumidifier filter. Clear the thermostat by touching “dismiss” after installing a fresh filter.
  • 186—Rinse ventilator core. Clear the thermostat by tapping “dismiss” after finishing this task.
  • 187—Clean or install a new ventilator filter. Clear the display by hitting “dismiss” after installing a new filter.
  • 188/189—Install a new UV bulb. Reach Service Experts Heating & Air Conditioning at 318-588-8163 for support.
  • 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 outside temperature. Get the Lyric app to finish 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 choose new Wi-Fi network.
  • 508—Wi-Fi not connected. Download the Lyric app and follow the procedures to connect your thermostat.

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

Our Experts are Available to Help

If you’re still experiencing problems after working through the troubleshooting list, our pros are available to assist you. Reach us at 318-588-8163 and we’ll come to your house as fast as we can to diagnose the issue.

If you have a dated thermostat, right now is a good time to think about a replacement. Thermostat technology has advanced in recent years Ask us for more info on how smart thermostats can make your home better while helping save on energy costs all year.

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