How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the best thermostat manufacturers, and we proudly install them on a usual basis in Tempe. They’re long-lasting and reliable. Plus, Honeywell is regularly updating its technology, offering more features for your house.

Nevertheless, all thermostats can have problems every now and then. As a result, we’ve compiled this helpful guide to go over troubleshooting.

While you can usually solve many thermostat problems by yourself, they often require Expert help. Our heating and cooling pros are here to assist you when you need us. We’re just a call away at 623-243-4517.

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

What Type of Thermostat Do I Have?

There are three models of thermostats:

  • Manual—This is the typical dial-shaped thermostat. You won’t run into error codes with this kind, but it’s also the least efficient for saving on energy expenses.
  • Programmable—This thermostat has a digital screen and arrows you touch to choose your desired temperature. You can also set daily programs to decrease the temperature when you’re away and raise it when you return.
  • Smart—You won’t have to schedule any programs on this thermostat, as it picks up on your schedule. It instinctively changes the temperature when you or other household members are away to help you save on heating and cooling bills. You can also change the temperature anywhere using your phone or other Wi-Fi-enabled device. 

As is the case with most technologically advanced solutions, there are several glitches that may occur. The majority of of these situations don’t require pro help and are easy to solve by yourself.

Common Honeywell Thermostat Problems

Every thermostat has a unique group of codes matching the issues that occur.

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

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

Display is Blank

If the display is empty on your programmable thermostat, you might 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 make sure the power is on for your furnace or air handler. Make sure the switch near the indoor equipment is switched “on”.

In addition to that, you should confirm all furnace cabinet or air handler doors/panels are sturdily in place.

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

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

Comfort System Won’t Start

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

In the summer, confirm you set the thermostat below the room temperature. When it’s cold, confirm it’s higher. This sounds silly, but we’ve seen it occur a lot of times.

Confirm the power switch by your indoor equipment is in the “on” position. You should also comfirm the cabinet doors or panels are closed on your furnace cabinet or air handler. An unsecured panel can trigger the safety switch, diverting current to the system.

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

“Cool On” or “Heat On” is Flickering

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

Then, ensure it’s telling the correct unit to start. This is often indicated by “cool on,” “heat on” or an illustration.

If this phrase or the picture is flashing, your thermostat is in a five-minute delay mode. This feature keeps your unit from damaging short cycling. This can occur if you lose electricity.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump needs service. Call Bob Brown Service Experts at 623-243-4517 for support.
  • 168—Wi-Fi radio error. Call 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 run.
  • 173—Thermostat temperature sensor error. Reach Lyric technical support at 800-633-3991.
  • 175—AC power restored. No action necessary.
  • 181/182—Install a new air filter. Clear the thermostat by touching “dismiss” after putting in a clean filter.
  • 184—Install a new humidifier pad. Clear the screen by tapping “dismiss” after putting in a clean pad filter.
  • 185—Put in a new dehumidifier filter. Clear the display by hitting “dismiss” after putting in a new filter.
  • 187—Rinse or install a new ventilator filter. Clear the thermostat by touching “dismiss” after putting in a fresh filter.
  • 188/189—Replace UV bulb. Call Bob Brown Service Experts at 623-243-4517 for help.
  • 210—Register online for exterior temperature. Download the Lyric app to do 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. 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 configured. Use the Lyric app and follow the process to configure your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump needs service. Reach Bob Brown Service Experts at 623-243-4517 for help.
  • 168—Wi-Fi radio error. Call Bob Brown Service Experts at 623-243-4517 for assistance.
  • 170—Internal memory error. Contact Bob Brown Service Experts at 623-243-4517 for support.
  • 171—Set date and time. Complete these settings so scheduling can work.
  • 173—Thermostat temperature sensor error. Reach Bob Brown Service Experts at 623-243-4517 for support.
  • 175—AC power resumed. No action necessary.
  • 177—Indoor temperature sensor error. Reach Bob Brown Service Experts at 623-243-4517 for assistance.
  • 178—Outdoor temperature sensor error. Call Bob Brown Service Experts at 623-243-4517 for support.
  • 181/182—Install a new air filter. Clear the thermostat by touching “dismiss” after putting in a new filter.
  • 183—Rinse humidifier tank and install a new water filter. Clear the thermostat by touching “dismiss” after completing these procedures.
  • 184—Replace humidifier pad. Clear the screen by hitting “dismiss” after installing pad filter.
  • 185—Replace dehumidifier filter. Clear the thermostat by touching “dismiss” after installing a clean filter.
  • 186—Wash ventilator core. Clear the display by tapping “dismiss” after doing this task.
  • 187—Wash or get a new ventilator filter. Clear the monitor by hitting “dismiss” after installing a new filter.
  • 188/189—Install a new UV bulb. Contact Bob Brown Service Experts at 623-243-4517 for assistance.
  • 210—Register online for outdoor temperature. Get the Lyric app to do this step and ensure correct thermostat operation.
  • 388—Register online for remote access and outdoor temperature. Use the Lyric app to finish this step and ensure proper thermostat operation.
  • 399—No Internet. Verify 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. Get the Lyric app and follow the process to connect your thermostat.

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

Our Experts are Available to Provide Support

If you’re still experiencing troubles after going through the troubleshooting list, our pros are ready to support you. Reach us at 623-243-4517 and we’ll be out quickly to determine the malfunction.

If you use an aging thermostat, now is a fantastic time to think about a replacement. Thermostat technology has come a long way over the last few years. Ask us for more details on how smart thermostats can make your residence more convenient while helping save on utility costs all year.

Contact Us