How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the top thermostat manufacturers, 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 residence.

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

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

Let’s start the process by finding out what model 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 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 choose 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 make any programs on this thermostat, since it learns your schedule. It automatically adjusts the temperature when you or other household members are gone to help you save on heating and cooling bills. You can also change the temperature anywhere via your phone or other Wi-Fi-enabled device. 

As you’re aware many technologically advanced products, there are common glitches that might occur. Many of these problems don’t require professional support and are simple to solve on your own.

Common Honeywell Thermostat Troubles

All thermostats have a unique kind of codes matching the glitches that occur.

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

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

Display is Blank

If the screen is empty on your programmable thermostat, you could 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 check the power is enabled for your furnace or air handler. Verify the switch near the indoor system is switched “on”.

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

A panel that isn’t tight may trigger the safety switch, which disconnects power to the system.

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

Heating and Cooling System Won’t Turn On

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

In the summer, make sure you schedule 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.

Confirm the power switch close to your indoor unit is in the “on” position. You should also comfirm 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 run? Make sure circuit breakers haven’t turned off and that your HVAC unit isn’t displaying error codes.

“Cool On” or “Heat On” is Blinking

First, verify your thermostat is set to “cool” or “heat.”

Then, make sure it’s calling for the appropriate system to run. This is typically indicated by “cool on,” “heat on” or an illustration.

If this phrase or the picture is pulsing, your thermostat is in a five-minute delay mode. This mode protects your equipment from harmful short cycling. This could 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. Reach 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 take place.
  • 173—Thermostat temperature sensor error. Reach Lyric technical support at 800-633-3991.
  • 175—AC power restarted. No action needed.
  • 181/182—Install a new air filter. Clear the thermostat by hitting “dismiss” after adding a new filter.
  • 184—Replace humidifier pad. Clear the thermostat by tapping “dismiss” after adding a fresh pad filter.
  • 185—Replace dehumidifier filter. Clear the thermostat by touching “dismiss” after adding a new filter.
  • 187—Clean or replace ventilator filter. Clear the monitor by touching “dismiss” after putting in a new filter.
  • 188/189—Get a new UV bulb. Call Barlow Service Experts at 801-436-8985 for help.
  • 210—Register online for exterior temperature. Download 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 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 up. Use the Lyric app and follow the process 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. Call Barlow Service Experts at 801-436-8985 for assistance.
  • 168—Wi-Fi radio error. Reach Barlow Service Experts at 801-436-8985 for assistance.
  • 170—Internal memory error. Call Barlow Service Experts at 801-436-8985 for support.
  • 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. Reach Barlow Service Experts at 801-436-8985 for support.
  • 178—Outdoor temperature sensor error. Call Barlow Service Experts at 801-436-8985 for help.
  • 181/182—Replace air filter. Clear the display by touching “dismiss” after adding a fresh filter.
  • 183—Clean humidifier tank and install a new water filter. Clear the thermostat by hitting “dismiss” after completing these tasks.
  • 184—Get a new humidifier pad. Clear the display 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 monitor 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 outside temperature. Download the Lyric app to complete 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. Download the Lyric app and follow the process to connect your thermostat.

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

Our Experts are Ready to Provide Assistance

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

If you have a dated thermostat, now is a great time to think over a new device. Thermostat technology has advanced lately Ask us for more details on how smart thermostats can make your house more convenient while helping save on energy bills year-round.

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