How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the leading thermostat manufacturers, and we proudly install them on a regular basis in Savannah. They’re sturdy and reliable. Also, Honeywell is regularly updating its technology, offering more features for your family.

However, every thermostat can run into problems once in awhile. That’s why we’ve compiled this informative guide to run through troubleshooting.

While you can usually repair many thermostat troubles by yourself, they sometimes require Expert assistance. Our heating and cooling pros are here to support you when you need us. We’re only a call away at 912-208-2399.

Let’s start the process by determining what model of thermostat your residence has.

What Type of Thermostat Do I Have?

There are three kinds of thermostats:

  • Manual—This is the typical dial-shaped thermostat. You won’t have error codes with this type, but it’s also the least efficient for saving on energy costs.
  • Programmable—This thermostat features a digital screen and arrows you touch to set your desired temperature. You can also use daily programs to reduce the temperature when you’re away and set it higher when you return.
  • Smart—You won’t have to set any programs on this thermostat, because it learns your routine. It automatically adjusts the temperature when you or other household members are gone to help you save on energy costs. You can also change the temperature anywhere on your phone or other Wi-Fi-enabled device. 

As is the case with the majority of technologically advanced solutions, there are several problems that might happen. The majority of of these troubles don’t require pro help and are easy to repair by yourself.

Common Honeywell Thermostat Problems

Each thermostat has a special group of codes matching the troubles that happen.

Think how easy it can be to fix a computer by restarting it. In most situations, diagnosing a thermostat can be just as easy.

Here is a listing the most reported Honeywell thermostat issues. These are applicable to the following programmable thermostats:

Display is Blank

If the monitor is empty on your programmable thermostat, you may need to put in new batteries. If that doesn’t take care of the issue or you rely on a smart thermostat, there might be a wiring malfunction.

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

Additionally, you should make sure all furnace cabinet or air handler doors/panels are securely secured.

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

Infrequently, a clear monitor could indicate you should replace your thermostat.

Comfort Unit Won’t Start

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

When it’s hot, confirm you schedule the thermostat lower than the current temperature. When it’s cold, verify it’s higher. This sounds goofy, but we’ve seen it happen lots of times.

Ensure the power switch near your indoor equipment 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 unsecured panel can trigger the safety switch, stopping electricity to the system.

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

“Cool On” or “Heat On” is Flashing

First, verify your thermostat is on “cool” or “heat.”

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

If these words or the picture is flashing, your thermostat is in a five-minute delay status. This mode protects your system from bad short cycling. This may happen if you lose power.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump must be serviced. Call Coastal Service Experts at 912-208-2399 for support.
  • 168—Wi-Fi radio error. Contact Lyric technical support at 800-633-3991. 170—Internal memory error. Call 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 restarted. No action needed.
  • 181/182—Install a new air filter. Clear the display by tapping “dismiss” after installing a new filter.
  • 184—Put in a new humidifier pad. Clear the display by tapping “dismiss” after adding a fresh pad filter.
  • 185—Install a new dehumidifier filter. Clear the screen by touching “dismiss” after putting in a fresh filter.
  • 187—Wash or install a new ventilator filter. Clear the display by touching “dismiss” after installing a clean filter.
  • 188/189—Get a new UV bulb. Contact Coastal Service Experts at 912-208-2399 for help.
  • 210—Register online for exterior temperature. Get the Lyric app to finish this step and ensure proper thermostat operation.
  • 388—Register online for remote access and exterior temperature. Get the Lyric app to finish this step and ensure correct 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 up. Get the Lyric app and follow the process to connect your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump requires service. Reach Coastal Service Experts at 912-208-2399 for support.
  • 168—Wi-Fi radio error. Contact Coastal Service Experts at 912-208-2399 for support.
  • 170—Internal memory error. Reach Coastal Service Experts at 912-208-2399 for support.
  • 171—Set date and time. Complete these settings so scheduling can work.
  • 173—Thermostat temperature sensor error. Reach Coastal Service Experts at 912-208-2399 for assistance.
  • 175—AC power reconnected. No action necessary.
  • 177—Indoor temperature sensor error. Reach Coastal Service Experts at 912-208-2399 for assistance.
  • 178—Outdoor temperature sensor error. Contact Coastal Service Experts at 912-208-2399 for support.
  • 181/182—Install a new air filter. Clear the display by hitting “dismiss” after installing a fresh filter.
  • 183—Clean humidifier tank and replace water filter. Clear the screen by tapping “dismiss” after doing these steps.
  • 184—Install a new humidifier pad. Clear the thermostat by hitting “dismiss” after adding a new pad filter.
  • 185—Install a new dehumidifier filter. Clear the display by hitting “dismiss” after adding a fresh filter.
  • 186—Clean ventilator core. Clear the screen by tapping “dismiss” after doing this task.
  • 187—Clean or get a new ventilator filter. Clear the monitor by tapping “dismiss” after buying a new filter.
  • 188/189—Install a new UV bulb. Contact Coastal Service Experts at 912-208-2399 for assistance.
  • 210—Register online for outdoor temperature. Download the Lyric app to do this step and ensure correct thermostat operation.
  • 388—Register online for remote access and exterior temperature. Use 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. Get the Lyric app and follow the procedures to connect your thermostat.

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

Our Experts are Here to Provide Assistance

If you’re still experiencing troubles after going through the troubleshooting steps, our professionals are available to assist you. Call us at 912-208-2399 and we’ll come to your house rapidly to diagnose the malfunction.

If you have a dated thermostat, now is a fantastic time to think over a new thermostat. Thermostat technology has come a long way over the last few years. Ask us for more details on how smart thermostats can make your house more convenient while helping save on heating and cooling expenses year-round.

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