How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the best thermostat brands, and we proudly install them on a frequent basis in Haltom City. They’re long-lasting and trustworthy. Plus, Honeywell is frequently advancing its technology, resulting in more features for your family.

Still, all thermostats can run into issues at times. That’s why we’ve put together this valuable guidebook to walk you through troubleshooting.

While you can often repair many thermostat problems alone, they sometimes need Expert help. Our home comfort Experts are ready to support you when you need us. We’re only a call away at 817-668-6689.

Let’s get started with the process by determining what kind of thermostat your residence has.

What Kind of Thermostat Do I Have?

There are three types 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 heating and cooling expenses.
  • Programmable—This thermostat includes a digital screen and arrows you touch to set your desired temperature. You can also use daily programs to decrease the temperature when you’re away and raise it when you come home.
  • Smart—You won’t have to schedule any programs on this thermostat, because it adjusts to your schedule. It instinctively changes the temperature when you or loved ones are away to help you save on utility costs. You can also change the temperature anywhere using your phone or other Wi-Fi-enabled device. 

As you know many technologically advanced products, there are common malfunctions that may take place. Many of these problems don’t call for pro assistance and are simple to solve by yourself.

Common Honeywell Thermostat Problems

Each thermostat has a special set of codes that correspond to the issues that take place.

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

Here is a guide to the most reported Honeywell thermostat issues. These apply to the following programmable thermostats:

Display is Blank

If the screen is blank on your programmable thermostat, you could need to install new batteries. If that doesn’t take care of the issue or you use a smart thermostat, there may be a wiring problem.

Next, you should check the power is enabled for your furnace or air handler. Verify the switch close to the indoor unit is switched “up”.

In addition to that, you should make certain all furnace cabinet or air handler doors/panels are tightly fastened.

An unsecured panel may trigger the safety switch, which cuts off power to the equipment.

Infrequently, an empty monitor can signify you need to buy a new thermostat.

HVAC Unit Won’t Run

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

In the summer, make sure you schedule the thermostat lower than the room temperature. When it’s cool, verify it’s higher. This sounds absurd, but we’ve seen it take place lots of times.

Make sure the power switch close to your indoor system is in the “on” position. You should also check 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 system.

System still won’t turn on? Verify circuit breakers haven’t turned off and that your HVAC system isn’t showing error codes.

“Cool On” or “Heat On” is Blinking

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

Then, check it’s telling the appropriate unit to start. This is typically shown by “cool on,” “heat on” or an icon.

If this phrase or the picture is pulsing, your thermostat is in a five-minute delay mode. This feature protects your unit from damaging short cycling. This could occur if you lose power.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump needs service. Call Stark Services at 817-668-6689 for help.
  • 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. Finish these settings so scheduling can run.
  • 173—Thermostat temperature sensor error. Call Lyric technical support at 800-633-3991.
  • 175—AC power resumed. No action required.
  • 181/182—Put in a new air filter. Clear the screen by hitting “dismiss” after putting in a clean filter.
  • 184—Install a new humidifier pad. Clear the screen by hitting “dismiss” after installing a new pad filter.
  • 185—Install a new dehumidifier filter. Clear the screen by tapping “dismiss” after adding a fresh filter.
  • 187—Clean or put in a new ventilator filter. Clear the monitor by hitting “dismiss” after installing a new filter.
  • 188/189—Install a new UV bulb. Call Stark Services at 817-668-6689 for help.
  • 210—Register online for exterior temperature. Use the Lyric app to finish this step and ensure proper thermostat operation.
  • 388—Register online for remote access and outside temperature. Download the Lyric app to do this step and ensure correct 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 set up. Download the Lyric app and follow the procedure to link your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump requires service. Reach Stark Services at 817-668-6689 for support.
  • 168—Wi-Fi radio error. Reach Stark Services at 817-668-6689 for assistance.
  • 170—Internal memory error. Contact Stark Services at 817-668-6689 for assistance.
  • 171—Set date and time. Finish these settings so scheduling can work.
  • 173—Thermostat temperature sensor error. Contact Stark Services at 817-668-6689 for help.
  • 175—AC power resumed. No action needed.
  • 177—Indoor temperature sensor error. Contact Stark Services at 817-668-6689 for assistance.
  • 178—Outdoor temperature sensor error. Contact Stark Services at 817-668-6689 for help.
  • 181/182—Install a new air filter. Clear the monitor by tapping “dismiss” after adding a clean filter.
  • 183—Wash humidifier tank and replace water filter. Clear the thermostat by touching “dismiss” after finishing these tasks.
  • 184—Replace humidifier pad. Clear the display by tapping “dismiss” after installing pad filter.
  • 185—Replace dehumidifier filter. Clear the monitor by tapping “dismiss” after adding a fresh filter.
  • 186—Rinse ventilator core. Clear the display by touching “dismiss” after finishing this task.
  • 187—Wash or get a new ventilator filter. Clear the display by touching “dismiss” after buying a new filter.
  • 188/189—Get a new UV bulb. Get in touch with Stark Services at 817-668-6689 for assistance.
  • 210—Register online for outside temperature. Use the Lyric app to complete this step and ensure accurate thermostat operation.
  • 388—Register online for remote access and exterior temperature. Get the Lyric app to complete 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 pick new Wi-Fi network.
  • 508—Wi-Fi not configured. Use the Lyric app and follow the procedures to connect your thermostat.

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

Our Experts are Ready to Help

If you’re still having problems after going through the troubleshooting list, our professionals are ready to help. Call us at 817-668-6689 and we’ll come to your house rapidly to determine the problem.

If you rely on a dated thermostat, now is a fantastic time to consider a new thermostat. Thermostat technology has advanced in recent years Ask us for more information on how smart thermostats can make your house comfier while helping save on heating and cooling expenses throughout the year.

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