How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the leading thermostat producers, and we proudly install them on a regular basis in Fort Lauderdale. They’re durable and trustworthy. In addition, Honeywell is frequently updating its technology, bringing more features for your household.

However, every thermostat can have problems every now and then. As a result, we’ve compiled this helpful guide to run through troubleshooting.

While you can often fix many thermostat troubles alone, they sometimes call for Expert support. Our heating and cooling professionals are here to support you when you need us. We’re merely a call away at 954-736-4314.

Let’s begin the process by figuring out what model of thermostat your residence has.

What Model of Thermostat Do I Have?

There are three models of thermostats:

  • Manual—This is the older dial-shaped thermostat. You won’t have error codes with this kind, but it’s also the least efficient for reducing heating and cooling bills.
  • Programmable—This thermostat includes a digital screen and arrows you use to set your desired temperature. You can also set daily programs to lower the temperature when you’re away and raise it when you get back.
  • Smart—You won’t have to schedule any programs on this thermostat, as it learns your day. It automatically adjusts the temperature when you or loved ones are gone to help you save on utility costs. You can also raise or lower the temperature anywhere via your phone or other Wi-Fi-enabled device. 

As you know many technologically advanced solutions, there are common malfunctions that can happen. Most of these problems don’t need pro assistance and are simple to repair by yourself.

Common Honeywell Thermostat Issues

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

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

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

Display is Blank

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

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

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

An unsecured panel may trip the safety switch, which cuts off power to the system.

While it’s less common, a clear screen can indicate you need to buy a new thermostat.

HVAC System Won’t Work

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

During warm weather, verify you schedule the thermostat lower than the current temperature. In the winter, confirm it’s higher. This sounds absurd, but we’ve seen it happen many times.

Confirm the power switch near your indoor equipment is in the “on” position. You should also check the cabinet doors or panels are secure on your furnace cabinet or air handler. A loose panel can trigger the safety switch, diverting current to the system.

Heating or cooling still won’t start? Verify circuit breakers haven’t turned off and that your HVAC system isn’t displaying error codes.

“Cool On” or “Heat On” is Flashing

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

Then, check it’s signaling the appropriate unit to turn on. This is typically demonstrated by “cool on,” “heat on” or an icon.

If this phrase or the illustration is pulsing, your thermostat is in a five-minute delay state. This mode protects your equipment from damaging short cycling. This may take place if you lose electricity.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump requires service. Call Service Experts Heating & Air Conditioning at 954-736-4314 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 run.
  • 173—Thermostat temperature sensor error. Contact Lyric technical support at 800-633-3991.
  • 175—AC power restored. No action required.
  • 181/182—Put in a new air filter. Clear the thermostat by tapping “dismiss” after installing a clean filter.
  • 184—Install a new humidifier pad. Clear the monitor by tapping “dismiss” after installing a clean pad filter.
  • 185—Install a new dehumidifier filter. Clear the thermostat by hitting “dismiss” after installing a new filter.
  • 187—Rinse or install a new ventilator filter. Clear the screen by touching “dismiss” after putting in a new filter.
  • 188/189—Install a new UV bulb. Call Service Experts Heating & Air Conditioning at 954-736-4314 for assistance.
  • 210—Register online for outdoor temperature. Use 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 finish this step and ensure proper 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 configured. Get the Lyric app and follow the procedure to connect your thermostat.

For more details, check 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 954-736-4314 for support.
  • 168—Wi-Fi radio error. Reach Service Experts Heating & Air Conditioning at 954-736-4314 for assistance.
  • 170—Internal memory error. Contact Service Experts Heating & Air Conditioning at 954-736-4314 for help.
  • 171—Set date and time. Finalize these settings so scheduling can operate.
  • 173—Thermostat temperature sensor error. Reach Service Experts Heating & Air Conditioning at 954-736-4314 for assistance.
  • 175—AC power reconnected. No action required.
  • 177—Indoor temperature sensor error. Call Service Experts Heating & Air Conditioning at 954-736-4314 for help.
  • 178—Outdoor temperature sensor error. Contact Service Experts Heating & Air Conditioning at 954-736-4314 for support.
  • 181/182—Get a new air filter. Clear the thermostat by touching “dismiss” after installing a clean filter.
  • 183—Wash humidifier tank and replace water filter. Clear the monitor by hitting “dismiss” after doing these steps.
  • 184—Replace humidifier pad. Clear the monitor by touching “dismiss” after installing pad filter.
  • 185—Replace dehumidifier filter. Clear the thermostat by hitting “dismiss” after installing a fresh filter.
  • 186—Clean ventilator core. Clear the screen by touching “dismiss” after finishing this task.
  • 187—Clean or replace ventilator filter. Clear the monitor by hitting “dismiss” after buying a new filter.
  • 188/189—Add a new UV bulb. Get in touch with Service Experts Heating & Air Conditioning at 954-736-4314 for help.
  • 210—Register online for outside temperature. Download the Lyric app to finish this step and ensure proper thermostat operation.
  • 388—Register online for remote access and outdoor temperature. Use the Lyric app to complete 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 pick new Wi-Fi network.
  • 508—Wi-Fi not set up. Get the Lyric app and follow the steps to connect your thermostat.

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

Our Experts are Available to Provide Assistance

If you’re still experiencing issues after trying the troubleshooting steps, our Experts are ready to support you. Reach us at 954-736-4314 and we’ll come to your house rapidly to diagnose the problem.

If you have an aging thermostat, right now is a fantastic time to consider a new thermostat. Thermostat technology has come a long way over the last few years. Ask us for more info on how smart thermostats can make your house comfier while helping save on energy costs year-round.

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