How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the leading thermostat manufacturers, and we proudly install them on a usual basis in Knoxville. They’re long-lasting and reliable. Also, Honeywell is regularly advancing its technology, bringing more features for your family.

Nevertheless, every thermostat can experience errors once in awhile. As a result, we’ve prepared this valuable guide to go over troubleshooting.

While you can usually fix many thermostat problems by yourself, they often call for Expert assistance. Our HVAC pros are ready to support you when you need us. We’re only a call away at 865-229-6176.

Let’s begin the process by finding out what kind of thermostat your residence 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 expenses.
  • Programmable—This thermostat has a digital screen and arrows you touch to determine your desired temperature. You can also set daily programs to reduce the temperature when you’re at work and set it higher when you return.
  • Smart—You won’t have to set any programs on this thermostat, as it adjusts to your day. It intuitively raises and lowers the temperature when you or other household members are out and about to help you save on heating and cooling expenses. You can also raise or lower the temperature anywhere via your phone or other Wi-Fi-enabled device. 

As you know many technologically advanced solutions, there are several problems that can occur. Many of these problems don’t require Expert assistance and are easy to solve alone.

Common Honeywell Thermostat Issues

Every thermostat has an exclusive set of codes assigned to the issues that take place.

Think how uncomplicated it can be to restore a computer by restarting it. In many instances, diagnosing a thermostat can be just as easy.

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

Display is Blank

If the display is clear on your programmable thermostat, you might need to replace the batteries. If that doesn’t take care of the trouble or you use a smart thermostat, there might be a wiring problem.

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

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

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

Less frequently, a clear screen could mean you need to replace your thermostat.

Heating and Cooling System Won’t Turn On

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

During warm weather, confirm you set the thermostat lower than the room temperature. When it’s cool, make sure it’s higher. This sounds absurd, but we’ve seen it take place many times.

Confirm the power switch by your indoor system is in the “on” position. You should also check the cabinet doors or panels are secure on your furnace cabinet or air handler. An unsecured panel can trip the safety switch, stopping current to the system.

Heating or cooling still won’t turn on? Verify circuit breakers haven’t flipped and that your HVAC equipment isn’t displaying error codes.

“Cool On” or “Heat On” is Blinking

To begin, check your thermostat is on “cool” or “heat.”

Then, check it’s signaling the correct system to run. This is typically shown by “cool on,” “heat on” or an illustration.

If this phrase or the illustration is flashing, your thermostat is in a five-minute delay status. This mode keeps your unit 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 R & M Climate Control Service Experts at 865-229-6176 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. Finalize these settings so scheduling can take place.
  • 173—Thermostat temperature sensor error. Call Lyric technical support at 800-633-3991.
  • 175—AC power restarted. No action needed.
  • 181/182—Replace air filter. Clear the screen by hitting “dismiss” after putting in a clean filter.
  • 184—Replace humidifier pad. Clear the thermostat by touching “dismiss” after installing a clean pad filter.
  • 185—Replace dehumidifier filter. Clear the screen by touching “dismiss” after putting in a new filter.
  • 187—Clean or replace ventilator filter. Clear the display by tapping “dismiss” after putting in a new filter.
  • 188/189—Replace UV bulb. Call R & M Climate Control Service Experts at 865-229-6176 for help.
  • 210—Register online for outside temperature. Get the Lyric app to finish this step and ensure accurate thermostat operation.
  • 388—Register online for remote access and outdoor temperature. Use the Lyric app to do 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 select new Wi-Fi network.
  • 508—Wi-Fi not set up. Download the Lyric app and follow the procedure to connect your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump needs service. Reach R & M Climate Control Service Experts at 865-229-6176 for support.
  • 168—Wi-Fi radio error. Contact R & M Climate Control Service Experts at 865-229-6176 for assistance.
  • 170—Internal memory error. Reach R & M Climate Control Service Experts at 865-229-6176 for help.
  • 171—Set date and time. Finalize these settings so scheduling can operate.
  • 173—Thermostat temperature sensor error. Call R & M Climate Control Service Experts at 865-229-6176 for support.
  • 175—AC power restored. No action required.
  • 177—Indoor temperature sensor error. Call R & M Climate Control Service Experts at 865-229-6176 for help.
  • 178—Outdoor temperature sensor error. Reach R & M Climate Control Service Experts at 865-229-6176 for support.
  • 181/182—Get a new air filter. Clear the thermostat by tapping “dismiss” after installing a clean filter.
  • 183—Rinse humidifier tank and replace water filter. Clear the screen by hitting “dismiss” after finishing these procedures.
  • 184—Replace humidifier pad. Clear the display by hitting “dismiss” after adding a new pad filter.
  • 185—Replace dehumidifier filter. Clear the screen by touching “dismiss” after adding a new filter.
  • 186—Wash ventilator core. Clear the display by tapping “dismiss” after finishing this task.
  • 187—Rinse or get a new ventilator filter. Clear the screen by touching “dismiss” after getting a new filter.
  • 188/189—Add a new UV bulb. Reach R & M Climate Control Service Experts at 865-229-6176 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 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 configured. Use the Lyric app and follow the procedures to connect your thermostat.

For more specifics, see this thermostat’s user manual.

Our Experts are Here to Provide Assistance

If you’re still running into troubles after trying the troubleshooting steps, our pros are ready to help. Call us at 865-229-6176 and we’ll come to your house quickly to diagnose the malfunction.

If you rely on a dated thermostat, right now is a great time to think about a new thermostat. Thermostat technology has come a long way over the last few years. Ask us for more info on how smart thermostats can make your residence more comfortable while helping save on heating and cooling costs throughout the year.

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