How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the top thermostat producers, and we proudly install them on a regular basis in Oklahoma City. They’re durable and dependable. Also, Honeywell is constantly improving its technology, offering more features for your family.

Still, every thermostat can run into issues from time to time. Due to this, we’ve put together this useful guidebook to run through troubleshooting.

While you can often fix the majority of thermostat problems by yourself, they often require Expert help. Our home comfort Experts are here to assist you when you need us. We’re only a call away at 405-432-2197.

Let’s begin the process by determining what kind of thermostat your residence has.

What Type of Thermostat Do I Have?

There are three types of thermostats:

  • Manual—This is the classic dial-shaped thermostat. You won’t experience error codes with this one, but it’s also the least efficient for reducing utility bills.
  • Programmable—This thermostat has a digital screen and arrows you press to set your desired temperature. You can also choose daily programs to decrease the temperature when you’re gone and raise it when you get back.
  • Smart—You won’t have to set any programs on this thermostat, as it learns your routine. It intuitively changes the temperature when you or family members are away 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 is the case with most technologically advanced things, there are several problems that might take place. The majority of of these problems don’t call for professional assistance and are easy to solve on your own.

Common Honeywell Thermostat Issues

Every thermostat has an exclusive set of codes that correspond to the problems that occur.

Think how simple it can be to repair a computer by restarting it. In many instances, troubleshooting a thermostat can be just as uncomplicated.

Here is a listing the most common Honeywell thermostat issues. These involve the following programmable thermostats:

Display is Blank

If the monitor is empty on your programmable thermostat, you might need to install new batteries. If that doesn’t solve the issue or you use a smart thermostat, there might be a wiring malfunction.

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

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

A panel that isn’t tight may trigger the safety switch, which cuts off power to the system.

Less frequently, a clear monitor might signify you should install a new thermostat.

Heating and Cooling Unit Won’t Run

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

In the summer, confirm you set the thermostat lower than the ambient temperature. When it’s cool, confirm it’s higher. This sounds absurd, but we’ve seen it occur a lot of 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 closed on your furnace cabinet or air handler. An open panel can trip the safety switch, cutting off electricity to the unit.

Heating or cooling still won’t start? Confirm circuit breakers haven’t flipped and that your HVAC system isn’t experiencing error codes.

“Cool On” or “Heat On” is Flashing

To begin, confirm your thermostat is set to “cool” or “heat.”

Then, check it’s telling the appropriate unit to run. This is usually indicated by “cool on,” “heat on” or an icon.

If this phrase or the picture is blinking, your thermostat is in a five-minute delay status. This mode stops your system from damaging short cycling. This could happen if you lose electricity.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump needs service. Call Gordon's Service Experts at 405-432-2197 for support.
  • 168—Wi-Fi radio error. Reach 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 take place.
  • 173—Thermostat temperature sensor error. Call Lyric technical support at 800-633-3991.
  • 175—AC power restarted. No action necessary.
  • 181/182—Replace air filter. Clear the thermostat by touching “dismiss” after putting in a fresh filter.
  • 184—Install a new humidifier pad. Clear the monitor by hitting “dismiss” after putting in a fresh pad filter.
  • 185—Replace dehumidifier filter. Clear the display by tapping “dismiss” after installing a clean filter.
  • 187—Wash or install a new ventilator filter. Clear the display by touching “dismiss” after adding a fresh filter.
  • 188/189—Replace UV bulb. Call Gordon's Service Experts at 405-432-2197 for assistance.
  • 210—Register online for outside 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 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 up. Get the Lyric app and follow the process to connect your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump needs service. Call Gordon's Service Experts at 405-432-2197 for assistance.
  • 168—Wi-Fi radio error. Call Gordon's Service Experts at 405-432-2197 for support.
  • 170—Internal memory error. Call Gordon's Service Experts at 405-432-2197 for help.
  • 171—Set date and time. Complete these settings so scheduling can run.
  • 173—Thermostat temperature sensor error. Contact Gordon's Service Experts at 405-432-2197 for help.
  • 175—AC power restored. No action needed.
  • 177—Indoor temperature sensor error. Call Gordon's Service Experts at 405-432-2197 for help.
  • 178—Outdoor temperature sensor error. Contact Gordon's Service Experts at 405-432-2197 for help.
  • 181/182—Replace air filter. Clear the thermostat by tapping “dismiss” after installing a new filter.
  • 183—Clean humidifier tank and replace water filter. Clear the screen by hitting “dismiss” after completing these procedures.
  • 184—Install a new humidifier pad. Clear the screen by tapping “dismiss” after adding a new pad filter.
  • 185—Get a new dehumidifier filter. Clear the thermostat by tapping “dismiss” after putting in a fresh filter.
  • 186—Rinse ventilator core. Clear the display by touching “dismiss” after completing this task.
  • 187—Wash or get a new ventilator filter. Clear the monitor by touching “dismiss” after getting a new filter.
  • 188/189—Replace UV bulb. Contact Gordon's Service Experts at 405-432-2197 for help.
  • 210—Register online for outdoor temperature. Use the Lyric app to finish this step and ensure proper thermostat operation.
  • 388—Register online for remote access and outdoor temperature. Get the Lyric app to do this step and ensure correct 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. Get the Lyric app and follow the procedures to connect your thermostat.

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

Our Experts are Here to Provide Assistance

If you’re still experiencing troubles after going through the troubleshooting process, our professionals are ready to help. Reach us at 405-432-2197 and we’ll be out as fast as we can to determine the problem.

If you have a dated thermostat, right now is a good time to think over a new device. Thermostat technology has gotten better over the last few years. Ask us for more information on how smart thermostats can make your house more comfortable while helping save on heating and cooling bills year-round.

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