How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the best thermostat manufacturers, and we proudly install them on a frequent basis in Charleston. They’re long-lasting and trustworthy. Plus, Honeywell is frequently improving its technology, bringing more features for your home.

Nevertheless, each thermostat can experience errors every so often. Due to this, we’ve put together this helpful manual to run through troubleshooting.

While you can typically repair the majority of thermostat issues on your own, they often call for Expert help. Our heating and cooling professionals are available to support you when you need us. We’re just a call away at 843-410-6103.

Let’s get started with the process by finding out what type of thermostat your house has.

What Type of Thermostat Do I Have?

There are three kinds of thermostats:

  • Manual—This is the typical dial-shaped thermostat. You won’t run into error codes with this kind, but it’s also the least efficient for saving on utility bills.
  • Programmable—This thermostat includes a digital screen and arrows you touch to set your desired temperature. You can also choose daily programs to reduce the temperature when you’re away and set it higher when you return.
  • Smart—You won’t have to make any programs on this thermostat, as it picks up on your routine. It automatically raises and lowers the temperature when you or other household members are gone to help you save on energy costs. 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 regular glitches that might occur. Many of these troubles don’t require Expert help and are uncomplicated enough to solve on your own.

Common Honeywell Thermostat Troubles

Each thermostat has a unique kind of codes matching the problems that take place.

Think how uncomplicated it can be to restore a computer by restarting it. In most cases, diagnosing a thermostat can be just as simple.

Here are some of the most common Honeywell thermostat issues. These involve the following programmable thermostats:

Display is Blank

If the display is empty on your programmable thermostat, you may need to put in new batteries. If that doesn’t solve the malfunction or you use a smart thermostat, there may be a wiring issue.

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

Also, you should confirm all furnace cabinet or air handler doors/panels are securely fastened.

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

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

HVAC System Won’t Work

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

When it’s hot, confirm you set the thermostat beneath the current temperature. In the winter, verify it’s higher. This sounds goofy, but we’ve seen it happen many times.

Ensure 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, cutting off power to the equipment.

Equipment still won’t turn on? Confirm circuit breakers haven’t turned off and that your HVAC system isn’t experiencing error codes.

“Cool On” or “Heat On” is Blinking

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

Then, verify it’s calling for the appropriate system to start. This is often shown by “cool on,” “heat on” or an icon.

If these words or the picture is flashing, your thermostat is in a five-minute delay status. This setting protects your equipment from damaging short cycling. This can occur if your power is interrupted.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump must be serviced. Call Pardee Service Experts at 843-410-6103 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. Complete these settings so scheduling can occur.
  • 173—Thermostat temperature sensor error. Call Lyric technical support at 800-633-3991.
  • 175—AC power resumed. No action required.
  • 181/182—Install a new air filter. Clear the display by hitting “dismiss” after putting in a new filter.
  • 184—Put in a new humidifier pad. Clear the screen by tapping “dismiss” after installing a fresh pad filter.
  • 185—Replace dehumidifier filter. Clear the display by hitting “dismiss” after adding a fresh filter.
  • 187—Clean or install a new ventilator filter. Clear the display by hitting “dismiss” after putting in a clean filter.
  • 188/189—Replace UV bulb. Ring Pardee Service Experts at 843-410-6103 for support.
  • 210—Register online for exterior temperature. Get the Lyric app to finish this step and ensure proper thermostat operation.
  • 388—Register online for remote access and exterior temperature. Get the Lyric app to complete 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 choose new Wi-Fi network.
  • 508—Wi-Fi not configured. Use the Lyric app and follow the process to configure your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump needs service. Reach Pardee Service Experts at 843-410-6103 for assistance.
  • 168—Wi-Fi radio error. Reach Pardee Service Experts at 843-410-6103 for assistance.
  • 170—Internal memory error. Call Pardee Service Experts at 843-410-6103 for assistance.
  • 171—Set date and time. Finalize these settings so scheduling can work.
  • 173—Thermostat temperature sensor error. Contact Pardee Service Experts at 843-410-6103 for help.
  • 175—AC power reconnected. No action required.
  • 177—Indoor temperature sensor error. Call Pardee Service Experts at 843-410-6103 for help.
  • 178—Outdoor temperature sensor error. Contact Pardee Service Experts at 843-410-6103 for help.
  • 181/182—Replace air filter. Clear the display by hitting “dismiss” after putting in a new filter.
  • 183—Clean humidifier tank and install a new water filter. Clear the screen by tapping “dismiss” after completing these steps.
  • 184—Install a new humidifier pad. Clear the thermostat by hitting “dismiss” after getting a new pad filter.
  • 185—Install a new dehumidifier filter. Clear the thermostat by hitting “dismiss” after installing a fresh filter.
  • 186—Rinse ventilator core. Clear the thermostat by hitting “dismiss” after finishing this task.
  • 187—Clean or install a new ventilator filter. Clear the screen by touching “dismiss” after installing a new filter.
  • 188/189—Replace UV bulb. Get in touch with Pardee Service Experts at 843-410-6103 for assistance.
  • 210—Register online for outdoor temperature. Use the Lyric app to do this step and ensure correct thermostat operation.
  • 388—Register online for remote access and exterior temperature. Download the Lyric app to finish 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 select new Wi-Fi network.
  • 508—Wi-Fi not set up. Download the Lyric app and follow the steps to connect your thermostat.

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

Our Experts are Available to Provide Assistance

If you’re still having problems after going through the troubleshooting list, our pros are available to help. Give us a call at 843-410-6103 and we’ll be out rapidly to diagnose the issue.

If you rely on a dated thermostat, now is a great time to consider a new device. Thermostat technology has come a long way in recent years Ask us for more info on how smart thermostats can make your home better while helping save on heating and cooling expenses year-round.

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