How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the leading thermostat brands, and we proudly install them on a usual basis in the Wasatch Front region. They’re sturdy and trustworthy. Also, Honeywell is frequently updating its technology, offering more features for your house.

Still, every thermostat can have troubles once in awhile. As a result, we’ve compiled this helpful guidebook to run through troubleshooting.

While you can typically repair many thermostat problems alone, they sometimes require Expert assistance. Our HVAC pros are here to help when you need us. We’re merely a call away at 801-436-8985.

Let’s start the process by determining what model of thermostat your residence 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 kind, but it’s also the least efficient for saving on heating and cooling bills.
  • Programmable—This thermostat has a digital screen and arrows you use to determine your desired temperature. You can also use daily programs to lower the temperature when you’re at work and set it higher when you come home.
  • Smart—You won’t have to schedule any programs on this thermostat, since it learns your schedule. It instinctively adjusts the temperature when you or other household members are gone to help you save on energy bills. You can also raise or lower the temperature anywhere via your phone or other Wi-Fi-enabled device. 

As you know the majority of technologically advanced products, there are common glitches that might occur. Many of these problems don’t require professional help and are uncomplicated enough to repair on your own.

Common Honeywell Thermostat Issues

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

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

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

Display is Blank

If the screen is clear on your programmable thermostat, you may need to put in new batteries. If that doesn’t solve the malfunction or you rely on a smart thermostat, there could be a wiring malfunction.

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

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

An unsecured panel may trigger the safety switch, which disconnects power to the system.

Less frequently, a clear monitor might mean you will need to install a new thermostat.

Comfort System Won’t Run

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

In the summer, make sure you put the thermostat lower than the current temperature. In the winter, confirm it’s higher. This sounds goofy, but we’ve seen it occur many times.

Ensure the power switch close to your indoor unit is in the “on” position. You should also check the cabinet doors or panels are secure on your furnace cabinet or air handler. A loose panel can activate the safety switch, cutting off power to the unit.

System still won’t start? Make sure circuit breakers haven’t turned off and that your HVAC equipment isn’t displaying error codes.

“Cool On” or “Heat On” is Flickering

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

Then, verify it’s calling for the appropriate system to run. This is typically indicated by “cool on,” “heat on” or a picture.

If this set of words or the illustration is blinking, your thermostat is in a five-minute delay mode. This mode protects your unit from harmful short cycling. This may happen if you lose power.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump needs service. Call Barlow Service Experts at 801-436-8985 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. Finalize these settings so scheduling can occur.
  • 173—Thermostat temperature sensor error. Contact Lyric technical support at 800-633-3991.
  • 175—AC power restored. No action necessary.
  • 181/182—Put in a new air filter. Clear the thermostat by tapping “dismiss” after putting in a new filter.
  • 184—Replace humidifier pad. Clear the thermostat by hitting “dismiss” after adding a fresh pad filter.
  • 185—Replace dehumidifier filter. Clear the thermostat by touching “dismiss” after putting in a new filter.
  • 187—Clean or replace ventilator filter. Clear the monitor by touching “dismiss” after putting in a new filter.
  • 188/189—Install a new UV bulb. Call Barlow Service Experts at 801-436-8985 for support.
  • 210—Register online for exterior temperature. Download the Lyric app to finish this step and ensure correct thermostat operation.
  • 388—Register online for remote access and exterior temperature. Get the Lyric app to do 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 select new Wi-Fi network.
  • 508—Wi-Fi not set. Get the Lyric app and follow the process to connect your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump needs service. Call Barlow Service Experts at 801-436-8985 for assistance.
  • 168—Wi-Fi radio error. Contact Barlow Service Experts at 801-436-8985 for assistance.
  • 170—Internal memory error. Call Barlow Service Experts at 801-436-8985 for help.
  • 171—Set date and time. Complete these settings so scheduling can operate.
  • 173—Thermostat temperature sensor error. Contact Barlow Service Experts at 801-436-8985 for support.
  • 175—AC power resumed. No action required.
  • 177—Indoor temperature sensor error. Contact Barlow Service Experts at 801-436-8985 for support.
  • 178—Outdoor temperature sensor error. Call Barlow Service Experts at 801-436-8985 for support.
  • 181/182—Replace air filter. Clear the display by touching “dismiss” after putting in a clean filter.
  • 183—Clean humidifier tank and add a new water filter. Clear the thermostat by hitting “dismiss” after completing these tasks.
  • 184—Get a new humidifier pad. Clear the screen by hitting “dismiss” after installing pad filter.
  • 185—Replace dehumidifier filter. Clear the display by hitting “dismiss” after putting in a clean filter.
  • 186—Clean ventilator core. Clear the screen by touching “dismiss” after doing this task.
  • 187—Wash or get a new ventilator filter. Clear the display by tapping “dismiss” after installing a new filter.
  • 188/189—Replace UV bulb. Get in touch with Barlow Service Experts at 801-436-8985 for assistance.
  • 210—Register online for outdoor temperature. Download the Lyric app to complete this step and ensure correct thermostat operation.
  • 388—Register online for remote access and exterior temperature. Download the Lyric app to complete this step and ensure accurate 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 connected. Download the Lyric app and follow the procedures to connect your thermostat.

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

Our Experts are Available to Provide Assistance

If you’re still running into issues after going through the troubleshooting list, our Experts are here to support you. Give us a call at 801-436-8985 and we’ll arrive quickly to diagnose the malfunction.

If you have an aging thermostat, now is a fantastic time to think about a new thermostat. Thermostat technology has advanced in recent years Ask us for more info on how smart thermostats can make your residence more convenient while helping save on energy bills year-round.

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