How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the top thermostat producers, and we proudly install them on a usual basis in Shreveport. They’re sturdy and reliable. In addition, Honeywell is frequently enhancing its technology, bringing more features for your family.

Nevertheless, all thermostats can experience issues now and then. Due to this, we’ve put together this valuable handbook to run through troubleshooting.

While you can often repair most thermostat problems on your own, they occasionally require Expert support. Our HVAC Experts are available to assist you when you need us. We’re just a call away at 318-588-8163.

Let’s begin the process by determining what model of thermostat your house has.

What Kind of Thermostat Do I Have?

There are three kinds of thermostats:

  • Manual—This is the classic 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 costs.
  • Programmable—This thermostat includes a digital screen and arrows you touch to choose your desired temperature. You can also choose daily programs to reduce the temperature when you’re gone and increase it when you return.
  • Smart—You won’t have to make any programs on this thermostat, because it adjusts to your day. It intuitively changes the temperature when you or family members are away to help you save on energy costs. You can also change the temperature anywhere via your phone or other Wi-Fi-enabled device. 

As you know many technologically advanced solutions, there are several glitches that may happen. Many of these troubles don’t need pro assistance and are simple to repair by yourself.

Common Honeywell Thermostat Issues

Every thermostat has an exclusive set of codes that correspond to the glitches that happen.

Think how uncomplicated it can be to fix a computer by restarting it. For the most part, correcting a thermostat can be just as easy.

Here are some of the most common Honeywell thermostat errors. These involve the following programmable thermostats:

Display is Blank

If the monitor is blank on your programmable thermostat, you might need to replace the batteries. If that doesn’t solve the issue 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. Verify the switch near the indoor system is switched “up”.

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

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

While it’s less common, an empty monitor can signify you need to buy a new thermostat.

HVAC Unit Won’t Work

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

When it’s hot, verify you schedule the thermostat beneath the room temperature. In the winter, confirm it’s higher. This sounds silly, but we’ve seen it happen many 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 closed on your furnace cabinet or air handler. An unsecured panel can trip the safety switch, cutting off current to the system.

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

“Cool On” or “Heat On” is Flickering

To begin, confirm your thermostat is switched to “cool” or “heat.”

Then, make sure it’s signaling the right system to turn on. This is typically shown by “cool on,” “heat on” or an icon.

If these words or the icon is flashing, your thermostat is in a five-minute delay status. This feature protects your system from harmful short cycling. This could happen if your power is interrupted.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump needs service. Call Service Experts Heating & Air Conditioning at 318-588-8163 for assistance.
  • 168—Wi-Fi radio error. Contact Lyric technical support at 800-633-3991. 170—Internal memory error. Contact Lyric technical support at 800-633-3991.
  • 171—Set date and time. Finish these settings so scheduling can occur.
  • 173—Thermostat temperature sensor error. Call Lyric technical support at 800-633-3991.
  • 175—AC power restarted. No action needed.
  • 181/182—Replace air filter. Clear the screen by hitting “dismiss” after putting in a new filter.
  • 184—Put in a new humidifier pad. Clear the screen by touching “dismiss” after adding a new pad filter.
  • 185—Install a new dehumidifier filter. Clear the monitor by touching “dismiss” after adding a clean filter.
  • 187—Clean or put in a new ventilator filter. Clear the thermostat by hitting “dismiss” after installing a fresh filter.
  • 188/189—Install a new UV bulb. Ring Service Experts Heating & Air Conditioning at 318-588-8163 for assistance.
  • 210—Register online for outdoor temperature. Get the Lyric app to complete this step and ensure proper thermostat operation.
  • 388—Register online for remote access and outdoor temperature. Download the Lyric app to do this step and ensure correct 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. Use the Lyric app and follow the procedure to link your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump needs service. Reach Service Experts Heating & Air Conditioning at 318-588-8163 for support.
  • 168—Wi-Fi radio error. Call Service Experts Heating & Air Conditioning at 318-588-8163 for support.
  • 170—Internal memory error. Call Service Experts Heating & Air Conditioning at 318-588-8163 for assistance.
  • 171—Set date and time. Complete these settings so scheduling can run.
  • 173—Thermostat temperature sensor error. Call Service Experts Heating & Air Conditioning at 318-588-8163 for assistance.
  • 175—AC power restored. No action needed.
  • 177—Indoor temperature sensor error. Contact Service Experts Heating & Air Conditioning at 318-588-8163 for help.
  • 178—Outdoor temperature sensor error. Call Service Experts Heating & Air Conditioning at 318-588-8163 for support.
  • 181/182—Get a new air filter. Clear the thermostat by touching “dismiss” after putting in a fresh filter.
  • 183—Clean humidifier tank and replace water filter. Clear the monitor by touching “dismiss” after completing these tasks.
  • 184—Replace humidifier pad. Clear the screen by tapping “dismiss” after adding a new pad filter.
  • 185—Get a new dehumidifier filter. Clear the thermostat by touching “dismiss” after installing a fresh filter.
  • 186—Rinse ventilator core. Clear the thermostat by hitting “dismiss” after completing this task.
  • 187—Clean or install a new ventilator filter. Clear the monitor by hitting “dismiss” after installing a new filter.
  • 188/189—Install a new UV bulb. Reach Service Experts Heating & Air Conditioning at 318-588-8163 for help.
  • 210—Register online for exterior temperature. Use the Lyric app to complete this step and ensure correct thermostat operation.
  • 388—Register online for remote access and outside temperature. Get the Lyric app to do 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 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 specifics, view this thermostat’s user manual.

Our Experts are Ready to Help

If you’re still running into problems after working through the troubleshooting list, our pros are available to assist you. Reach us at 318-588-8163 and we’ll arrive as fast as we can to diagnose the issue.

If you have an aging thermostat, right now is a good time to think about a replacement. Thermostat technology has advanced in recent years Ask us for more info on how smart thermostats can make your home better while helping save on energy costs all year.

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