How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the best thermostat brands, and we proudly install them on a frequent basis in Hurricane. They’re durable and reliable. Also, Honeywell is frequently improving its technology, offering more features for your household.

Nevertheless, all thermostats can have troubles once in awhile. Due to this, we’ve put together this informative manual to go over troubleshooting.

While you can usually solve the majority of thermostat issues on your own, they often need Expert assistance. Our HVAC Experts are here to help when you need us. We’re merely a call away at 304-760-5088.

Let’s begin the process by determining what model of thermostat your home has.

What Kind of Thermostat Do I Have?

There are three models of thermostats:

  • Manual—This is the classic 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 choose your desired temperature. You can also choose daily programs to lower the temperature when you’re gone and increase it when you return.
  • Smart—You won’t have to schedule any programs on this thermostat, as it picks up on your day. It intuitively changes the temperature when you or other household members are out and about to help you save on heating and cooling costs. You can also raise or lower the temperature anywhere via your phone or other Wi-Fi-enabled device. 

As you know most technologically advanced products, there are several problems that may occur. Many of these situations don’t need Expert assistance and are simple to solve alone.

Common Honeywell Thermostat Problems

Each thermostat has an exclusive set of codes that correspond to the malfunctions that take place.

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

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

Display is Blank

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

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

Additionally, you should make sure all furnace cabinet or air handler doors/panels are tightly in place.

An unsecured panel may activate the safety switch, which disconnects power to the system.

While it’s less common, an empty screen may mean you need to buy a new thermostat.

Heating and Cooling Equipment Won’t Work

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

In the summer, verify you schedule the thermostat beneath the ambient temperature. When it’s cold, confirm it’s higher. This sounds silly, but we’ve seen it occur lots of times.

Make sure the power switch close to your indoor system is in the “on” position. You should also comfirm the cabinet doors or panels are tight on your furnace cabinet or air handler. An open panel can trip the safety switch, stopping power to the unit.

Equipment still won’t start? 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, confirm your thermostat is switched to “cool” or “heat.”

Then, verify it’s signaling the correct unit to start. This is typically demonstrated by “cool on,” “heat on” or a picture.

If this set of words or the illustration is flashing, your thermostat is in a five-minute delay status. This mode protects your unit from damaging 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 must be serviced. Call Teays Valley Service Experts at 304-760-5088 for assistance.
  • 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 take place.
  • 173—Thermostat temperature sensor error. Contact Lyric technical support at 800-633-3991.
  • 175—AC power resumed. No action needed.
  • 181/182—Replace air filter. Clear the thermostat by tapping “dismiss” after installing a clean filter.
  • 184—Replace humidifier pad. Clear the screen by touching “dismiss” after putting in a new pad filter.
  • 185—Replace dehumidifier filter. Clear the thermostat by tapping “dismiss” after adding a clean filter.
  • 187—Wash or put in a new ventilator filter. Clear the thermostat by touching “dismiss” after installing a new filter.
  • 188/189—Replace UV bulb. Contact Teays Valley Service Experts at 304-760-5088 for assistance.
  • 210—Register online for exterior temperature. Get the Lyric app to complete this step and ensure correct thermostat operation.
  • 388—Register online for remote access and outside temperature. Use the Lyric app to finish 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 choose new Wi-Fi network.
  • 508—Wi-Fi not set up. Download the Lyric app and follow the process to connect your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump must be serviced service. Call Teays Valley Service Experts at 304-760-5088 for assistance.
  • 168—Wi-Fi radio error. Reach Teays Valley Service Experts at 304-760-5088 for support.
  • 170—Internal memory error. Reach Teays Valley Service Experts at 304-760-5088 for assistance.
  • 171—Set date and time. Finish these settings so scheduling can operate.
  • 173—Thermostat temperature sensor error. Call Teays Valley Service Experts at 304-760-5088 for help.
  • 175—AC power restored. No action needed.
  • 177—Indoor temperature sensor error. Call Teays Valley Service Experts at 304-760-5088 for assistance.
  • 178—Outdoor temperature sensor error. Call Teays Valley Service Experts at 304-760-5088 for assistance.
  • 181/182—Replace air filter. Clear the monitor by hitting “dismiss” after installing a new filter.
  • 183—Rinse humidifier tank and install a new water filter. Clear the monitor by tapping “dismiss” after doing these procedures.
  • 184—Get a new humidifier pad. Clear the screen by tapping “dismiss” after adding a new pad filter.
  • 185—Replace dehumidifier filter. Clear the screen by touching “dismiss” after adding a fresh filter.
  • 186—Clean ventilator core. Clear the display by touching “dismiss” after completing this task.
  • 187—Wash or install a new ventilator filter. Clear the display by hitting “dismiss” after installing a new filter.
  • 188/189—Get a new UV bulb. Contact Teays Valley Service Experts at 304-760-5088 for assistance.
  • 210—Register online for exterior temperature. Get the Lyric app to finish this step and ensure accurate thermostat operation.
  • 388—Register online for remote access and outside temperature. Get the Lyric app to complete 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 select new Wi-Fi network.
  • 508—Wi-Fi not connected. Get the Lyric app and follow the steps to connect your thermostat.

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

Our Experts are Available to Provide Support

If you’re still having issues after trying the troubleshooting steps, our professionals are available to support you. Give us a call at 304-760-5088 and we’ll come to your house quickly to determine the issue.

If you use 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 home comfier while helping save on utility expenses throughout the year.

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