How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the best thermostat brands, and we proudly install them on a regular basis in Indianapolis. They’re long-lasting and reliable. Also, Honeywell is regularly enhancing its technology, offering more features for your home.

Nevertheless, all thermostats can run into issues once in awhile. Due to this, we’ve put together this valuable manual to go over troubleshooting.

While you can often solve many thermostat issues on your own, they occasionally require Expert help. Our HVAC Experts are ready to support you when you need us. We’re only a call away at 317-527-0271.

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

What Model of Thermostat Do I Have?

There are three models of thermostats:

  • Manual—This is the older dial-shaped thermostat. You won’t have error codes with this type, but it’s also the least efficient for lowering heating and cooling bills.
  • Programmable—This thermostat features a digital screen and arrows you touch to determine your desired temperature. You can also use daily programs to reduce the temperature when you’re gone and set it higher when you return.
  • Smart—You won’t have to set any programs on this thermostat, because it picks up on your routine. It automatically raises and lowers the temperature when you or loved ones 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 is the case with many technologically advanced products, there are several problems that may take place. The majority of of these issues don’t require Expert help and are uncomplicated enough to solve by yourself.

Common Honeywell Thermostat Problems

Each thermostat has an exclusive kind of codes matching the glitches that happen.

Think how simple it can be to fix a computer by restarting it. Many times, diagnosing a thermostat can be just as uncomplicated.

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

Display is Blank

If the monitor is blank on your programmable thermostat, you could need to put in new batteries. If that doesn’t take care of the problem or you use a smart thermostat, there could be a wiring malfunction.

Next, you should ensure the power is on for your furnace or air handler. Confirm the switch near the indoor system is switched “up”.

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

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

While it’s less common, an empty screen may signify you should install a new thermostat.

Heating and Cooling Unit Won’t Start

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

During warm weather, verify you set the thermostat below the room temperature. When it’s cool, verify it’s higher. This sounds absurd, but we’ve seen it take place lots of times.

Ensure the power switch by 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 unsecured panel can activate the safety switch, cutting off power to the system.

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

“Cool On” or “Heat On” is Blinking

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

Then, check it’s calling for the appropriate system to start. This is often shown by “cool on,” “heat on” or an illustration.

If this set of words or the illustration is flashing, your thermostat is in a five-minute delay mode. This feature keeps your unit from bad short cycling. This can happen if you lose electricity.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump must be serviced. Call Broad Ripple Service Experts at 317-527-0271 for support.
  • 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 take place.
  • 173—Thermostat temperature sensor error. Reach Lyric technical support at 800-633-3991.
  • 175—AC power restored. No action necessary.
  • 181/182—Replace air filter. Clear the monitor by touching “dismiss” after installing a new filter.
  • 184—Put in a new humidifier pad. Clear the display by touching “dismiss” after putting in a clean pad filter.
  • 185—Install a new dehumidifier filter. Clear the thermostat by hitting “dismiss” after installing a clean filter.
  • 187—Wash or install a new ventilator filter. Clear the screen by tapping “dismiss” after putting in a new filter.
  • 188/189—Replace UV bulb. Contact Broad Ripple Service Experts at 317-527-0271 for assistance.
  • 210—Register online for outside temperature. Download the Lyric app to complete this step and ensure correct thermostat operation.
  • 388—Register online for remote access and outdoor temperature. Use 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 choose new Wi-Fi network.
  • 508—Wi-Fi not configured. Download the Lyric app and follow the procedure to connect your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump needs service. Reach Broad Ripple Service Experts at 317-527-0271 for help.
  • 168—Wi-Fi radio error. Reach Broad Ripple Service Experts at 317-527-0271 for support.
  • 170—Internal memory error. Reach Broad Ripple Service Experts at 317-527-0271 for help.
  • 171—Set date and time. Finalize these settings so scheduling can operate.
  • 173—Thermostat temperature sensor error. Reach Broad Ripple Service Experts at 317-527-0271 for help.
  • 175—AC power reconnected. No action necessary.
  • 177—Indoor temperature sensor error. Call Broad Ripple Service Experts at 317-527-0271 for support.
  • 178—Outdoor temperature sensor error. Reach Broad Ripple Service Experts at 317-527-0271 for support.
  • 181/182—Install a new air filter. Clear the monitor by touching “dismiss” after putting in a clean filter.
  • 183—Rinse humidifier tank and add a new water filter. Clear the display by hitting “dismiss” after finishing these tasks.
  • 184—Get a new humidifier pad. Clear the display by hitting “dismiss” after installing pad filter.
  • 185—Install a new dehumidifier filter. Clear the monitor by touching “dismiss” after adding a fresh filter.
  • 186—Clean ventilator core. Clear the thermostat by tapping “dismiss” after doing this task.
  • 187—Wash or replace ventilator filter. Clear the screen by tapping “dismiss” after getting a new filter.
  • 188/189—Replace UV bulb. Get in touch with Broad Ripple Service Experts at 317-527-0271 for support.
  • 210—Register online for outdoor temperature. Use the Lyric app to do this step and ensure accurate thermostat operation.
  • 388—Register online for remote access and outside temperature. Use 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 pick new Wi-Fi network.
  • 508—Wi-Fi not configured. Get the Lyric app and follow the procedures to connect your thermostat.

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

Our Experts are Available to Provide Assistance

If you’re still running into problems after going through the troubleshooting list, our pros are available to assist you. Call us at 317-527-0271 and we’ll be out rapidly to diagnose the problem.

If you have an older thermostat, right now is a great time to think about a new device. Thermostat technology has come a long way over the last few years. Ask us for more information on how smart thermostats can make your house better while helping save on utility costs all year.

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