How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the top thermostat producers, and we proudly install them on a usual basis in Edmonton. They’re durable and trustworthy. Also, Honeywell is constantly updating its technology, offering more features for your family.

Still, all thermostats can experience problems at times. Due to this, we’ve prepared this informative manual to run through troubleshooting.

While you can usually repair the majority of thermostat issues by yourself, they often need Expert assistance. Our heating and cooling Experts are available to support you when you need us. We’re merely a call away at 780-800-9047.

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

What Kind of Thermostat Do I Have?

There are three models of thermostats:

  • Manual—This is the older dial-shaped thermostat. You won’t run into error codes with this one, but it’s also the least efficient for reducing utility bills.
  • Programmable—This thermostat features a digital screen and arrows you touch to choose your desired temperature. You can also choose daily programs to decrease the temperature when you’re away and increase it when you return.
  • Smart—You won’t have to schedule any programs on this thermostat, since it learns your routine. It automatically raises and lowers the temperature when you or loved ones are away to help you save on utility costs. You can also raise or lower the temperature anywhere on your phone or other Wi-Fi-enabled device. 

As is the case with many technologically advanced products, there are regular malfunctions that may take place. Many of these issues don’t require Expert support and are easy to fix by yourself.

Common Honeywell Thermostat Problems

All thermostats have a unique kind of codes matching the troubles that take place.

Think how simple it can be to repair a computer by restarting it. In most cases, correcting a thermostat can be just as easy.

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

Display is Blank

If the screen is empty on your programmable thermostat, you might need to replace the batteries. If that doesn’t solve the malfunction or you have a smart thermostat, there could be a wiring malfunction.

Next, you should check the power is flowing for your furnace or air handler. Confirm the switch close to the indoor unit is switched “up”.

Additionally, you should make sure all furnace cabinet or air handler doors/panels are sturdily in place.

An unsecured panel may activate the safety switch, which cuts off power to the unit.

Less frequently, a blank monitor can indicate you will need to install a new thermostat.

Comfort Unit Won’t Turn On

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

During warm weather, make sure you set the thermostat below the current temperature. When it’s cold, make sure it’s higher. This sounds goofy, but we’ve seen it take place lots of times.

Confirm the power switch close to your indoor equipment is in the “on” position. You should also make sure the cabinet doors or panels are tight on your furnace cabinet or air handler. An unsecured panel can trigger the safety switch, cutting off electricity to the unit.

Unit still won’t start? Confirm circuit breakers haven’t turned off and that your HVAC unit isn’t experiencing error codes.

“Cool On” or “Heat On” is Flickering

To start, confirm your thermostat is on “cool” or “heat.”

Then, make sure it’s calling for the appropriate system to start. This is usually demonstrated 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 mode keeps your system from harmful short cycling. This may occur if you lose power.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump needs service. Call Rob's Albertan Service Experts at 780-800-9047 for help.
  • 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. Complete these settings so scheduling can take place.
  • 173—Thermostat temperature sensor error. Contact Lyric technical support at 800-633-3991.
  • 175—AC power restarted. No action required.
  • 181/182—Put in a new air filter. Clear the monitor by touching “dismiss” after adding a clean filter.
  • 184—Replace humidifier pad. Clear the thermostat by tapping “dismiss” after adding a fresh pad filter.
  • 185—Put in a new dehumidifier filter. Clear the display by tapping “dismiss” after installing a clean filter.
  • 187—Wash or replace ventilator filter. Clear the display by hitting “dismiss” after adding a fresh filter.
  • 188/189—Install a new UV bulb. Ring Rob's Albertan Service Experts at 780-800-9047 for support.
  • 210—Register online for exterior temperature. Download the Lyric app to finish this step and ensure correct 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. 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. Get the Lyric app and follow the steps to configure 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. Reach Rob's Albertan Service Experts at 780-800-9047 for help.
  • 168—Wi-Fi radio error. Reach Rob's Albertan Service Experts at 780-800-9047 for support.
  • 170—Internal memory error. Call Rob's Albertan Service Experts at 780-800-9047 for support.
  • 171—Set date and time. Finish these settings so scheduling can work.
  • 173—Thermostat temperature sensor error. Call Rob's Albertan Service Experts at 780-800-9047 for assistance.
  • 175—AC power restored. No action required.
  • 177—Indoor temperature sensor error. Call Rob's Albertan Service Experts at 780-800-9047 for assistance.
  • 178—Outdoor temperature sensor error. Call Rob's Albertan Service Experts at 780-800-9047 for support.
  • 181/182—Install a new air filter. Clear the screen by hitting “dismiss” after installing a fresh filter.
  • 183—Rinse humidifier tank and install a new water filter. Clear the screen by hitting “dismiss” after doing these steps.
  • 184—Get a new humidifier pad. Clear the thermostat by hitting “dismiss” after adding a new pad filter.
  • 185—Get a new dehumidifier filter. Clear the thermostat by touching “dismiss” after installing a clean filter.
  • 186—Clean ventilator core. Clear the screen by touching “dismiss” after completing this task.
  • 187—Clean or install a new ventilator filter. Clear the monitor by touching “dismiss” after installing a new filter.
  • 188/189—Get a new UV bulb. Reach Rob's Albertan Service Experts at 780-800-9047 for assistance.
  • 210—Register online for exterior temperature. Use the Lyric app to finish this step and ensure proper thermostat operation.
  • 388—Register online for remote access and exterior temperature. Use the Lyric app to do 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 choose new Wi-Fi network.
  • 508—Wi-Fi not set up. Get the Lyric app and follow the procedures to connect your thermostat.

For more details, look at this thermostat’s user manual.

Our Experts are Here to Provide Support

If you’re still having issues after working through the troubleshooting steps, our professionals are ready to support you. Reach us at 780-800-9047 and we’ll come to your house as fast as we can to determine the issue.

If you rely on an older thermostat, now is a good time to think about a new device. Thermostat technology has advanced lately Ask us for more info on how smart thermostats can make your house more convenient while helping save on energy costs year-round.

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