How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the leading thermostat brands, and we proudly install them on a regular basis in Richmond. They’re durable and dependable. Plus, Honeywell is regularly enhancing its technology, offering more features for your house.

However, every thermostat can experience issues at times. As a result, we’ve compiled this informative manual to go over troubleshooting.

While you can usually solve many thermostat problems alone, they occasionally require Expert help. Our home comfort Experts are available to assist you when you need us. We’re only a call away at 804-548-4480.

Let’s begin the process by finding out what kind of thermostat your home has.

What Model of Thermostat Do I Have?

There are three models of thermostats:

  • Manual—This is the classic dial-shaped thermostat. You won’t have error codes with this one, but it’s also the least efficient for lowering energy costs.
  • Programmable—This thermostat includes a digital screen and arrows you touch to choose your desired temperature. You can also use daily programs to lower the temperature when you’re at work and increase it when you get back.
  • Smart—You won’t have to schedule any programs on this thermostat, since it learns your schedule. It instinctively changes the temperature when you or other household members are gone to help you save on energy expenses. You can also adjust the temperature anywhere using your phone or other Wi-Fi-enabled device. 

As is the case with the majority of technologically advanced solutions, there are common glitches that may take place. Most of these issues don’t require pro help and are uncomplicated enough to repair alone.

Common Honeywell Thermostat Problems

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

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

Here is a guide to the most encountered Honeywell thermostat problems. These apply to the following programmable thermostats:

Display is Blank

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

Next, you should make sure the power is on for your furnace or air handler. Verify the switch close to the indoor system is switched “up”.

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

An unsecured panel may trip the safety switch, which disconnects power to the equipment.

While it’s less common, a blank screen might indicate you should buy a new thermostat.

Heating and Cooling System Won’t Work

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

When it’s hot, verify you set the thermostat lower than the room temperature. When it’s cool, verify it’s higher. This sounds goofy, but we’ve seen it happen lots of times.

Make sure 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. An open panel can trip the safety switch, stopping power to the unit.

Heating or cooling still won’t turn on? Confirm circuit breakers haven’t flipped and that your HVAC system isn’t displaying error codes.

“Cool On” or “Heat On” is Blinking

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

Then, ensure it’s signaling the correct unit to start. This is typically demonstrated by “cool on,” “heat on” or an illustration.

If this phrase or the illustration is pulsing, your thermostat is in a five-minute delay status. This mode keeps your equipment 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 requires service. Call Eveready Service Experts at 804-548-4480 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 occur.
  • 173—Thermostat temperature sensor error. Reach Lyric technical support at 800-633-3991.
  • 175—AC power resumed. No action needed.
  • 181/182—Put in a new air filter. Clear the display by hitting “dismiss” after putting in a fresh filter.
  • 184—Install a new humidifier pad. Clear the screen by hitting “dismiss” after installing a new pad filter.
  • 185—Install a new dehumidifier filter. Clear the monitor by touching “dismiss” after putting in a new filter.
  • 187—Clean or replace ventilator filter. Clear the display by touching “dismiss” after installing a new filter.
  • 188/189—Install a new UV bulb. Call Eveready Service Experts at 804-548-4480 for help.
  • 210—Register online for outdoor temperature. Download the Lyric app to finish this step and ensure proper thermostat operation.
  • 388—Register online for remote access and exterior temperature. Download the Lyric app to finish this step and ensure accurate thermostat operation.
  • 399—No Internet. Verify 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. Get the Lyric app and follow the procedure to link your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump needs service. Call Eveready Service Experts at 804-548-4480 for assistance.
  • 168—Wi-Fi radio error. Contact Eveready Service Experts at 804-548-4480 for help.
  • 170—Internal memory error. Call Eveready Service Experts at 804-548-4480 for support.
  • 171—Set date and time. Finalize these settings so scheduling can operate.
  • 173—Thermostat temperature sensor error. Call Eveready Service Experts at 804-548-4480 for help.
  • 175—AC power resumed. No action needed.
  • 177—Indoor temperature sensor error. Contact Eveready Service Experts at 804-548-4480 for support.
  • 178—Outdoor temperature sensor error. Contact Eveready Service Experts at 804-548-4480 for help.
  • 181/182—Replace air filter. Clear the monitor by touching “dismiss” after putting in a new filter.
  • 183—Clean humidifier tank and install a new water filter. Clear the thermostat by touching “dismiss” after finishing these steps.
  • 184—Install a new humidifier pad. Clear the screen by hitting “dismiss” after adding a new pad filter.
  • 185—Get a new dehumidifier filter. Clear the monitor by hitting “dismiss” after adding a fresh filter.
  • 186—Rinse ventilator core. Clear the display by touching “dismiss” after finishing this task.
  • 187—Wash 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 Eveready Service Experts at 804-548-4480 for help.
  • 210—Register online for exterior temperature. Get the Lyric app to complete this step and ensure accurate thermostat operation.
  • 388—Register online for remote access and exterior temperature. Download the Lyric app to finish 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 select new Wi-Fi network.
  • 508—Wi-Fi not connected. Use the Lyric app and follow the process to connect your thermostat.

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

Our Experts are Here to Provide Assistance

If you’re still experiencing troubles after trying the troubleshooting steps, our pros are available to assist you. Reach us at 804-548-4480 and we’ll be out as fast as we can to diagnose the problem.

If you have an aging thermostat, today is a fantastic time to consider a replacement. Thermostat technology has advanced lately Ask us for more information on how smart thermostats can make your residence more convenient while helping save on energy expenses year-round.

Contact Us