How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the best thermostat brands, and we proudly install them on a regular basis in Dallas. They’re durable and reliable. In addition, Honeywell is constantly advancing its technology, bringing more features for your household.

However, every thermostat can run into errors every now and then. Due to this, we’ve put together this useful handbook to run through troubleshooting.

While you can often repair the majority of thermostat problems by yourself, they often need Expert assistance. Our HVAC professionals are ready to help when you need us. We’re only a call away at 469-250-0932.

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

What Type of Thermostat Do I Have?

There are three kinds of thermostats:

  • Manual—This is the typical dial-shaped thermostat. You won’t run into error codes with this one, but it’s also the least efficient for reducing heating and cooling bills.
  • Programmable—This thermostat features a digital screen and arrows you press to determine your desired temperature. You can also choose daily programs to decrease the temperature when you’re away and set it higher when you return.
  • Smart—You won’t have to set any programs on this thermostat, as it adjusts to your routine. It instinctively adjusts the temperature when you or other household members are gone to help you save on energy costs. You can also adjust the temperature anywhere using your phone or other Wi-Fi-enabled device. 

As you’re aware the majority of technologically advanced things, there are common glitches that can take place. Most of these issues don’t call for Expert assistance and are simple to solve by yourself.

Common Honeywell Thermostat Issues

Every thermostat has a unique set of codes assigned to the glitches that take place.

Think how simple it can be to restore a computer by restarting it. Many times, correcting a thermostat can be just as easy.

Here are some of the most encountered Honeywell thermostat errors. These are applicable to the following programmable thermostats:

Display is Blank

If the screen is empty on your programmable thermostat, you may need to get new batteries. If that doesn’t solve the issue or you have a smart thermostat, there could be a wiring malfunction.

Next, you should make sure the power is enabled for your furnace or air handler. Confirm the switch near the indoor system is in the “on” position.

Also, you should make certain all furnace cabinet or air handler doors/panels are tightly in place.

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

Infrequently, a blank monitor can mean you need to get a new thermostat.

HVAC System Won’t Turn On

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

During warm weather, confirm you put the thermostat lower than the current temperature. When it’s cool, make sure it’s higher. This sounds goofy, but we’ve seen it take place lots of times.

Make sure the power switch by your indoor system 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 activate the safety switch, cutting off electricity to the equipment.

System still won’t turn on? Verify circuit breakers haven’t tripped and that your HVAC unit isn’t experiencing error codes.

“Cool On” or “Heat On” is Blinking

First, make sure your thermostat is switched to “cool” or “heat.”

Then, verify it’s signaling the appropriate equipment to start. This is usually indicated by “cool on,” “heat on” or a picture.

If this set of words or the icon is pulsing, your thermostat is in a five-minute delay mode. This setting keeps your system from bad short cycling. This could occur if you lose electricity.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump requires service. Call Levy & Son Service Experts at 469-250-0932 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. Reach Lyric technical support at 800-633-3991.
  • 175—AC power resumed. No action required.
  • 181/182—Put in a new air filter. Clear the display by hitting “dismiss” after adding a clean filter.
  • 184—Put in a new humidifier pad. Clear the thermostat by hitting “dismiss” after adding a clean pad filter.
  • 185—Install a new dehumidifier filter. Clear the monitor by touching “dismiss” after installing a clean filter.
  • 187—Rinse or replace ventilator filter. Clear the display by tapping “dismiss” after installing a clean filter.
  • 188/189—Replace UV bulb. Ring Levy & Son Service Experts at 469-250-0932 for help.
  • 210—Register online for outside temperature. Download the Lyric app to finish this step and ensure accurate thermostat operation.
  • 388—Register online for remote access and outdoor temperature. Get the Lyric app to finish 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 pick new Wi-Fi network.
  • 508—Wi-Fi not set up. Use the Lyric app and follow the process to link your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump needs service. Contact Levy & Son Service Experts at 469-250-0932 for support.
  • 168—Wi-Fi radio error. Reach Levy & Son Service Experts at 469-250-0932 for support.
  • 170—Internal memory error. Contact Levy & Son Service Experts at 469-250-0932 for assistance.
  • 171—Set date and time. Finish these settings so scheduling can work.
  • 173—Thermostat temperature sensor error. Contact Levy & Son Service Experts at 469-250-0932 for help.
  • 175—AC power restored. No action required.
  • 177—Indoor temperature sensor error. Contact Levy & Son Service Experts at 469-250-0932 for help.
  • 178—Outdoor temperature sensor error. Call Levy & Son Service Experts at 469-250-0932 for assistance.
  • 181/182—Install a new air filter. Clear the screen by touching “dismiss” after installing a new filter.
  • 183—Wash humidifier tank and add a new water filter. Clear the monitor by tapping “dismiss” after finishing these steps.
  • 184—Get a new humidifier pad. Clear the screen by touching “dismiss” after adding a new pad filter.
  • 185—Replace dehumidifier filter. Clear the thermostat by tapping “dismiss” after installing a fresh filter.
  • 186—Rinse ventilator core. Clear the display by touching “dismiss” after finishing this task.
  • 187—Wash or install a new ventilator filter. Clear the monitor by touching “dismiss” after buying a new filter.
  • 188/189—Add a new UV bulb. Get in touch with Levy & Son Service Experts at 469-250-0932 for help.
  • 210—Register online for outside temperature. Get the Lyric app to complete this step and ensure correct thermostat operation.
  • 388—Register online for remote access and outside temperature. Download the Lyric app to complete 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 connected. Get the Lyric app and follow the steps to connect your thermostat.

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

Our Experts are Available to Provide Support

If you’re still having troubles after trying the troubleshooting process, our pros are available to help. Reach us at 469-250-0932 and we’ll arrive quickly to determine the malfunction.

If you have an aging thermostat, right now is a fantastic time to think about a new device. Thermostat technology has advanced over the last few years. Ask us for more info on how smart thermostats can make your home comfier while helping save on heating and cooling bills year-round.

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