How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the top thermostat manufacturers, and we proudly install them on a frequent basis in Raleigh. They’re durable and trustworthy. Also, Honeywell is frequently advancing its technology, bringing more features for your home.

However, each thermostat can run into issues now and then. As a result, we’ve put together this informative manual to go over troubleshooting.

While you can usually repair most thermostat problems on your own, they sometimes call for Expert help. Our HVAC pros are ready to assist you when you need us. We’re merely a call away at 919-578-4329.

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

What Model of Thermostat Do I Have?

There are three types of thermostats:

  • Manual—This is the older dial-shaped thermostat. You won’t experience error codes with this kind, but it’s also the least efficient for lowering heating and cooling expenses.
  • Programmable—This thermostat has a digital screen and arrows you use to choose your desired temperature. You can also use daily programs to reduce the temperature when you’re away and increase it when you come home.
  • Smart—You won’t have to schedule any programs on this thermostat, because it learns your day. It instinctively raises and lowers the temperature when you or other household members are gone to help you save on heating and cooling expenses. You can also raise or lower the temperature anywhere via your phone or other Wi-Fi-enabled device. 

As you know many technologically advanced products, there are regular glitches that might occur. Many of these issues don’t require professional help and are uncomplicated enough to solve by yourself.

Common Honeywell Thermostat Issues

Each thermostat has a unique set of codes matching the troubles that happen.

Think how easy it can be to restore a computer by restarting it. Many times, correcting a thermostat can be just as easy.

Here is a listing the most encountered Honeywell thermostat problems. These include the following programmable thermostats:

Display is Blank

If the monitor is blank on your programmable thermostat, you might need to get new batteries. If that doesn’t solve the issue or you have a smart thermostat, there could be a wiring malfunction.

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

Also, you should make certain all furnace cabinet or air handler doors/panels are sturdily fastened.

A loose panel may trip the safety switch, which stops power to the system.

While it’s less common, a clear screen may signify you should buy a new thermostat.

HVAC Equipment Won’t Run

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

In the summer, confirm you put the thermostat beneath the room temperature. In the winter, make sure it’s higher. This sounds absurd, but we’ve seen it take place many times.

Make sure the power switch near 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. A loose panel can trigger the safety switch, diverting power to the unit.

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

“Cool On” or “Heat On” is Blinking

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

Then, verify it’s signaling the right unit to start. This is typically demonstrated by “cool on,” “heat on” or an icon.

If this set of words or the picture is pulsing, your thermostat is in a five-minute delay status. This mode keeps your equipment from harmful short cycling. This can occur if you lose power.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump needs service. Call Service Experts Heating & Air Conditioning at 919-578-4329 for support.
  • 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. Complete these settings so scheduling can occur.
  • 173—Thermostat temperature sensor error. Reach 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 touching “dismiss” after adding a new filter.
  • 184—Put in a new humidifier pad. Clear the screen by tapping “dismiss” after putting in a clean pad filter.
  • 185—Put in a new dehumidifier filter. Clear the display by tapping “dismiss” after putting in a new filter.
  • 187—Clean or install a new ventilator filter. Clear the monitor by tapping “dismiss” after adding a clean filter.
  • 188/189—Install a new UV bulb. Contact Service Experts Heating & Air Conditioning at 919-578-4329 for help.
  • 210—Register online for exterior temperature. Get the Lyric app to finish this step and ensure accurate thermostat operation.
  • 388—Register online for remote access and outdoor temperature. Get the Lyric app to finish 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 choose new Wi-Fi network.
  • 508—Wi-Fi not set up. 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 must be serviced service. Contact Service Experts Heating & Air Conditioning at 919-578-4329 for support.
  • 168—Wi-Fi radio error. Contact Service Experts Heating & Air Conditioning at 919-578-4329 for assistance.
  • 170—Internal memory error. Call Service Experts Heating & Air Conditioning at 919-578-4329 for assistance.
  • 171—Set date and time. Finalize these settings so scheduling can work.
  • 173—Thermostat temperature sensor error. Call Service Experts Heating & Air Conditioning at 919-578-4329 for help.
  • 175—AC power reconnected. No action required.
  • 177—Indoor temperature sensor error. Reach Service Experts Heating & Air Conditioning at 919-578-4329 for support.
  • 178—Outdoor temperature sensor error. Call Service Experts Heating & Air Conditioning at 919-578-4329 for assistance.
  • 181/182—Replace air filter. Clear the screen by hitting “dismiss” after adding a new filter.
  • 183—Wash humidifier tank and install a new water filter. Clear the thermostat by tapping “dismiss” after doing these procedures.
  • 184—Get a new humidifier pad. Clear the display by touching “dismiss” after installing pad filter.
  • 185—Get a new dehumidifier filter. Clear the screen by hitting “dismiss” after putting in a fresh filter.
  • 186—Rinse ventilator core. Clear the display by tapping “dismiss” after completing this task.
  • 187—Clean or get a new ventilator filter. Clear the screen by touching “dismiss” after installing a new filter.
  • 188/189—Install a new UV bulb. Reach Service Experts Heating & Air Conditioning at 919-578-4329 for help.
  • 210—Register online for exterior temperature. Use 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 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 connected. Get the Lyric app and follow the process to connect your thermostat.

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

Our Experts are Available to Help

If you’re still having troubles after working through the troubleshooting process, our professionals are ready to assist you. Give us a call at 919-578-4329 and we’ll come to your house as fast as we can to figure out the malfunction.

If you have an aging thermostat, today is a great time to think about a replacement. Thermostat technology has gotten better over the last few years. Ask us for more details on how smart thermostats can make your residence better while helping save on utility costs all year.

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