How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the best thermostat manufacturers, and we proudly install them on a regular basis in San Antonio. They’re durable and dependable. Also, Honeywell is frequently updating its technology, offering more features for your house.

Nevertheless, every thermostat can experience problems every now and then. As a result, we’ve compiled this useful handbook to walk you through troubleshooting.

While you can typically fix the majority of thermostat problems alone, they occasionally require Expert help. Our home comfort Experts are ready to support you when you need us. We’re merely a call away at 210-404-4233.

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

What Model of Thermostat Do I Have?

There are three kinds of thermostats:

  • Manual—This is the typical dial-shaped thermostat. You won’t have error codes with this one, but it’s also the least efficient for saving on energy expenses.
  • Programmable—This thermostat features a digital screen and arrows you press to choose your desired temperature. You can also set daily programs to lower the temperature when you’re at work and set it higher when you return.
  • Smart—You won’t have to schedule any programs on this thermostat, because it adjusts to your schedule. It intuitively raises and lowers the temperature when you or loved ones are gone to help you save on energy bills. You can also adjust the temperature anywhere on your phone or other Wi-Fi-enabled device. 

As you’re aware most technologically advanced products, there are common problems that can occur. Many of these problems don’t call for Expert help and are simple to fix alone.

Common Honeywell Thermostat Problems

All thermostats have a unique kind of codes matching the malfunctions that happen.

Think how easy it can be to fix a computer by restarting it. In most situations, troubleshooting a thermostat can be just as easy.

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

Display is Blank

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

Next, you should make sure the power is flowing for your furnace or air handler. Verify the switch by the indoor equipment is switched “up”.

Additionally, you should confirm all furnace cabinet or air handler doors/panels are tightly fastened.

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

While it’s less common, an empty screen can indicate you need to install a new thermostat.

HVAC Equipment Won’t Turn On

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

During warm weather, make sure you set the thermostat lower than the room temperature. In the winter, make sure it’s higher. This sounds absurd, but we’ve seen it occur lots of times.

Make sure the power switch close to your indoor system is in the “on” position. You should also comfirm the cabinet doors or panels are secure on your furnace cabinet or air handler. An unsecured panel can trip the safety switch, stopping electricity to the system.

System still won’t run? Make sure circuit breakers haven’t turned off and that your HVAC system isn’t showing error codes.

“Cool On” or “Heat On” is Flickering

To start, check your thermostat is switched to “cool” or “heat.”

Then, ensure it’s telling the appropriate equipment to turn on. This is usually indicated by “cool on,” “heat on” or a picture.

If this phrase or the illustration is blinking, your thermostat is in a five-minute delay status. This setting protects your system from damaging short cycling. This may occur if you lose power.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump needs service. Call Aramendia Plumbing, Heating and Air at 210-404-4233 for support.
  • 168—Wi-Fi radio error. Call Lyric technical support at 800-633-3991. 170—Internal memory error. Reach Lyric technical support at 800-633-3991.
  • 171—Set date and time. Complete these settings so scheduling can run.
  • 173—Thermostat temperature sensor error. Contact Lyric technical support at 800-633-3991.
  • 175—AC power restored. No action required.
  • 181/182—Replace air filter. Clear the monitor by hitting “dismiss” after installing a new filter.
  • 184—Install a new humidifier pad. Clear the display by touching “dismiss” after putting in a clean pad filter.
  • 185—Put in a new dehumidifier filter. Clear the display by touching “dismiss” after installing a clean filter.
  • 187—Rinse or put in a new ventilator filter. Clear the monitor by hitting “dismiss” after putting in a clean filter.
  • 188/189—Get a new UV bulb. Contact Aramendia Plumbing, Heating and Air at 210-404-4233 for assistance.
  • 210—Register online for exterior temperature. Download the Lyric app to do this step and ensure correct thermostat operation.
  • 388—Register online for remote access and outside temperature. Get the Lyric app to finish this step and ensure proper 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 set. Download the Lyric app and follow the procedure to configure 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 Aramendia Plumbing, Heating and Air at 210-404-4233 for help.
  • 168—Wi-Fi radio error. Reach Aramendia Plumbing, Heating and Air at 210-404-4233 for assistance.
  • 170—Internal memory error. Reach Aramendia Plumbing, Heating and Air at 210-404-4233 for help.
  • 171—Set date and time. Finalize these settings so scheduling can work.
  • 173—Thermostat temperature sensor error. Call Aramendia Plumbing, Heating and Air at 210-404-4233 for assistance.
  • 175—AC power reconnected. No action necessary.
  • 177—Indoor temperature sensor error. Call Aramendia Plumbing, Heating and Air at 210-404-4233 for support.
  • 178—Outdoor temperature sensor error. Reach Aramendia Plumbing, Heating and Air at 210-404-4233 for help.
  • 181/182—Replace air filter. Clear the thermostat by hitting “dismiss” after putting in a clean filter.
  • 183—Wash humidifier tank and add a new water filter. Clear the thermostat by hitting “dismiss” after finishing these tasks.
  • 184—Replace humidifier pad. Clear the display by hitting “dismiss” after installing pad filter.
  • 185—Install a new dehumidifier filter. Clear the display by hitting “dismiss” after installing a fresh filter.
  • 186—Rinse ventilator core. Clear the screen by tapping “dismiss” after completing this task.
  • 187—Wash or install a new ventilator filter. Clear the monitor by hitting “dismiss” after installing a new filter.
  • 188/189—Replace UV bulb. Get in touch with Aramendia Plumbing, Heating and Air at 210-404-4233 for support.
  • 210—Register online for exterior temperature. Download the Lyric app to do this step and ensure proper thermostat operation.
  • 388—Register online for remote access and outdoor temperature. Get the Lyric app to do this step and ensure proper 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. Download the Lyric app and follow the steps to connect your thermostat.

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

Our Experts are Available to Provide Assistance

If you’re still experiencing issues after trying the troubleshooting process, our pros are here to help. Call us at 210-404-4233 and we’ll come to your house quickly to determine the malfunction.

If you use an aging thermostat, right now is a good time to think over a replacement. Thermostat technology has gotten better lately Ask us for more information on how smart thermostats can make your home more comfortable while helping save on energy expenses all year.

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