How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the top thermostat manufacturers, and we proudly install them on a usual basis in Winnipeg. They’re durable and trustworthy. Also, Honeywell is regularly advancing its technology, offering more features for your household.

However, all thermostats can run into issues at times. As a result, we’ve put together this valuable handbook to walk you through troubleshooting.

While you can usually repair most thermostat troubles on your own, they occasionally call for Expert help. Our heating and cooling professionals are available to support you when you need us. We’re only a call away at 204-800-0613.

Let’s begin the process by determining what type of thermostat your residence has.

What Kind of Thermostat Do I Have?

There are three models of thermostats:

  • Manual—This is the classic dial-shaped thermostat. You won’t run into error codes with this type, but it’s also the least efficient for lowering heating and cooling bills.
  • Programmable—This thermostat has a digital screen and arrows you press to choose your desired temperature. You can also choose daily programs to lower the temperature when you’re at work and increase it when you come home.
  • Smart—You won’t have to set any programs on this thermostat, because it learns your schedule. It intuitively raises and lowers the temperature when you or family members are away to help you save on energy expenses. You can also raise or lower the temperature anywhere on your phone or other Wi-Fi-enabled device. 

As you’re aware many technologically advanced products, there are common glitches that can happen. Many of these situations don’t call for Expert assistance and are uncomplicated enough to fix on your own.

Common Honeywell Thermostat Troubles

Each thermostat has a special set of codes that correspond to the malfunctions that happen.

Think how simple it can be to repair a computer by restarting it. Many times, troubleshooting a thermostat can be just as easy.

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

Display is Blank

If the monitor is clear on your programmable thermostat, you might need to put in new batteries. If that doesn’t take care of the trouble or you have a smart thermostat, there may be a wiring malfunction.

Next, you should ensure the power is on for your furnace or air handler. Verify the switch by the indoor unit is in the “on” position.

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

An unsecured panel may activate the safety switch, which stops power to the equipment.

Less frequently, an empty monitor may mean you need to get a new thermostat.

Heating and Cooling System Won’t Run

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

In the summer, make sure you put the thermostat beneath the ambient temperature. In the winter, confirm it’s higher. This sounds silly, but we’ve seen it happen many times.

Ensure the power switch by 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 unsecured panel can trigger the safety switch, stopping electricity to the unit.

Heating or cooling still won’t run? Make sure circuit breakers haven’t flipped and that your HVAC system isn’t displaying error codes.

“Cool On” or “Heat On” is Flickering

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

Then, make sure it’s signaling the right equipment to turn on. This is usually indicated by “cool on,” “heat on” or a picture.

If this set of words or the picture is flashing, your thermostat is in a five-minute delay state. This setting keeps your system from bad short cycling. This can happen if you lose electricity.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump requires service. Call Winnipeg Supply Service Experts at 204-800-0613 for assistance.
  • 168—Wi-Fi radio error. Call Lyric technical support at 800-633-3991. 170—Internal memory error. Call Lyric technical support at 800-633-3991.
  • 171—Set date and time. Finalize these settings so scheduling can run.
  • 173—Thermostat temperature sensor error. Contact Lyric technical support at 800-633-3991.
  • 175—AC power restarted. No action needed.
  • 181/182—Replace air filter. Clear the screen by tapping “dismiss” after adding a fresh filter.
  • 184—Install a new humidifier pad. Clear the screen by tapping “dismiss” after adding a fresh pad filter.
  • 185—Install a new dehumidifier filter. Clear the monitor by hitting “dismiss” after installing a fresh filter.
  • 187—Wash or replace ventilator filter. Clear the screen by hitting “dismiss” after putting in a clean filter.
  • 188/189—Install a new UV bulb. Call Winnipeg Supply Service Experts at 204-800-0613 for help.
  • 210—Register online for outside temperature. Use the Lyric app to do this step and ensure accurate 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. Verify 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. Download the Lyric app and follow the steps to link your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump needs service. Call Winnipeg Supply Service Experts at 204-800-0613 for support.
  • 168—Wi-Fi radio error. Contact Winnipeg Supply Service Experts at 204-800-0613 for support.
  • 170—Internal memory error. Call Winnipeg Supply Service Experts at 204-800-0613 for support.
  • 171—Set date and time. Complete these settings so scheduling can work.
  • 173—Thermostat temperature sensor error. Call Winnipeg Supply Service Experts at 204-800-0613 for help.
  • 175—AC power reconnected. No action required.
  • 177—Indoor temperature sensor error. Contact Winnipeg Supply Service Experts at 204-800-0613 for assistance.
  • 178—Outdoor temperature sensor error. Contact Winnipeg Supply Service Experts at 204-800-0613 for help.
  • 181/182—Replace air filter. Clear the screen by tapping “dismiss” after adding a fresh filter.
  • 183—Clean humidifier tank and replace water filter. Clear the screen by touching “dismiss” after finishing these procedures.
  • 184—Install a new humidifier pad. Clear the thermostat by touching “dismiss” after installing pad filter.
  • 185—Install a new dehumidifier filter. Clear the screen by hitting “dismiss” after adding a new filter.
  • 186—Wash ventilator core. Clear the monitor by touching “dismiss” after doing this task.
  • 187—Rinse or install a new ventilator filter. Clear the monitor by tapping “dismiss” after installing a new filter.
  • 188/189—Replace UV bulb. Contact Winnipeg Supply Service Experts at 204-800-0613 for assistance.
  • 210—Register online for exterior temperature. Use the Lyric app to do this step and ensure correct thermostat operation.
  • 388—Register online for remote access and outdoor temperature. Download the Lyric app to complete 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 pick new Wi-Fi network.
  • 508—Wi-Fi not configured. Download the Lyric app and follow the process to connect your thermostat.

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

Our Experts are Ready to Help

If you’re still having troubles after going through the troubleshooting process, our pros are ready to help. Give us a call at 204-800-0613 and we’ll be out quickly to determine the problem.

If you have a dated thermostat, today is a good time to think over a new thermostat. Thermostat technology has come a long way lately Ask us for more details on how smart thermostats can make your house better while helping save on energy expenses year-round.

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