How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the best thermostat brands, and we proudly install them on a usual basis in Kansas City. They’re durable and trustworthy. Plus, Honeywell is constantly improving its technology, bringing more features for your household.

However, each thermostat can experience issues now and again. Due to this, we’ve prepared this informative guidebook to run through troubleshooting.

While you can often repair many thermostat troubles on your own, they sometimes need Expert help. Our HVAC pros are here to help when you need us. We’re merely a call away at 816-787-0500.

Let’s get started with the process by figuring out what type of thermostat your residence has.

What Type of Thermostat Do I Have?

There are three kinds of thermostats:

  • Manual—This is the older dial-shaped thermostat. You won’t experience error codes with this kind, but it’s also the least efficient for reducing heating and cooling bills.
  • Programmable—This thermostat features a digital screen and arrows you touch to determine your desired temperature. You can also set daily programs to lower the temperature when you’re away and set it higher when you come home.
  • Smart—You won’t have to set any programs on this thermostat, since it picks up on your schedule. 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 change the temperature anywhere on your phone or other Wi-Fi-enabled device. 

As you know many technologically advanced products, there are several glitches that might take place. The majority of of these troubles don’t require pro support and are easy to fix alone.

Common Honeywell Thermostat Issues

Every thermostat has a special set of codes matching the malfunctions that occur.

Think how simple it can be to repair a computer by restarting it. In most situations, correcting a thermostat can be just as easy.

Here is a listing the most reported Honeywell thermostat problems. These include 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 fix the malfunction or you rely on a smart thermostat, there may be a wiring issue.

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

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

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

Less frequently, an empty monitor may mean you need to replace your thermostat.

Heating and Cooling System Won’t Start

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

In the summer, verify you schedule the thermostat lower than the ambient temperature. When it’s cool, confirm it’s higher. This sounds goofy, but we’ve seen it happen many times.

Make sure the power switch near your indoor equipment is in the “on” position. You should also comfirm the cabinet doors or panels are tight on your furnace cabinet or air handler. A loose panel can trip the safety switch, stopping electricity to the unit.

Equipment still won’t run? Confirm circuit breakers haven’t flipped and that your HVAC system isn’t experiencing error codes.

“Cool On” or “Heat On” is Flickering

To start, verify your thermostat is on “cool” or “heat.”

Then, make sure it’s telling the correct equipment to turn on. This is usually indicated by “cool on,” “heat on” or an icon.

If these words or the illustration is pulsing, your thermostat is in a five-minute delay mode. This setting keeps your equipment from damaging short cycling. This may occur if you lose electricity.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump must be serviced. Call Neal Harris Service Experts at 816-787-0500 for help.
  • 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. Complete these settings so scheduling can run.
  • 173—Thermostat temperature sensor error. Call Lyric technical support at 800-633-3991.
  • 175—AC power restarted. No action needed.
  • 181/182—Put in a new air filter. Clear the thermostat by touching “dismiss” after putting in a fresh filter.
  • 184—Put in a new humidifier pad. Clear the monitor by tapping “dismiss” after adding a clean pad filter.
  • 185—Put in a new dehumidifier filter. Clear the monitor by hitting “dismiss” after adding a fresh filter.
  • 187—Wash or replace ventilator filter. Clear the screen by tapping “dismiss” after installing a fresh filter.
  • 188/189—Get a new UV bulb. Contact Neal Harris Service Experts at 816-787-0500 for support.
  • 210—Register online for outside temperature. Download the Lyric app to do this step and ensure accurate thermostat operation.
  • 388—Register online for remote access and outdoor temperature. Download the Lyric app to do this step and ensure accurate 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. Get the Lyric app and follow the procedure to configure your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump requires service. Call Neal Harris Service Experts at 816-787-0500 for help.
  • 168—Wi-Fi radio error. Contact Neal Harris Service Experts at 816-787-0500 for help.
  • 170—Internal memory error. Reach Neal Harris Service Experts at 816-787-0500 for help.
  • 171—Set date and time. Finish these settings so scheduling can work.
  • 173—Thermostat temperature sensor error. Call Neal Harris Service Experts at 816-787-0500 for assistance.
  • 175—AC power restored. No action necessary.
  • 177—Indoor temperature sensor error. Call Neal Harris Service Experts at 816-787-0500 for support.
  • 178—Outdoor temperature sensor error. Contact Neal Harris Service Experts at 816-787-0500 for help.
  • 181/182—Install a new air filter. Clear the monitor by touching “dismiss” after installing a fresh filter.
  • 183—Wash humidifier tank and add a new water filter. Clear the screen by touching “dismiss” after finishing these tasks.
  • 184—Get a new humidifier pad. Clear the display by touching “dismiss” after adding a new pad filter.
  • 185—Install a new dehumidifier filter. Clear the monitor by touching “dismiss” after adding a clean filter.
  • 186—Rinse ventilator core. Clear the display by tapping “dismiss” after completing this task.
  • 187—Clean or replace ventilator filter. Clear the display by tapping “dismiss” after buying a new filter.
  • 188/189—Replace UV bulb. Reach Neal Harris Service Experts at 816-787-0500 for support.
  • 210—Register online for exterior temperature. Use the Lyric app to do this step and ensure accurate thermostat operation.
  • 388—Register online for remote access and outside temperature. Get the Lyric app to finish 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 choose new Wi-Fi network.
  • 508—Wi-Fi not set up. Get the Lyric app and follow the procedures to connect your thermostat.

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

Our Experts are Ready to Provide Support

If you’re still running into problems after working through the troubleshooting steps, our pros are here to support you. Give us a call at 816-787-0500 and we’ll come to your house as fast as we can to figure out the issue.

If you use an older thermostat, today is a great time to think over a replacement. Thermostat technology has gotten better over the last few years. Ask us for more information on how smart thermostats can make your house better while helping save on heating and cooling bills throughout the year.

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