How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the best thermostat brands, and we proudly install them on a frequent basis in Charleston. They’re long-lasting and trustworthy. In addition, Honeywell is frequently improving its technology, offering more features for your family.

Still, each thermostat can run into issues now and again. As a result, we’ve put together this helpful guide to run through troubleshooting.

While you can often repair many thermostat troubles on your own, they occasionally call for Expert help. Our heating and cooling Experts are here to support you when you need us. We’re merely a call away at 843-410-6103.

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

What Type 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 type, but it’s also the least efficient for saving on energy bills.
  • Programmable—This thermostat includes a digital screen and arrows you use to set your desired temperature. You can also use daily programs to reduce the temperature when you’re gone and increase it when you return.
  • Smart—You won’t have to make any programs on this thermostat, as it adjusts to your routine. It automatically changes the temperature when you or other household members are out and about to help you save on heating and cooling costs. You can also adjust the temperature anywhere using your phone or other Wi-Fi-enabled device. 

As is the case with many technologically advanced solutions, there are several glitches that might occur. Many of these troubles don’t require pro help and are uncomplicated enough to solve on your own.

Common Honeywell Thermostat Issues

Each thermostat has a unique group of codes that correspond to the problems that take place.

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

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

Display is Blank

If the display is clear on your programmable thermostat, you could need to put in new batteries. If that doesn’t solve the malfunction or you rely on 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 make certain all furnace cabinet or air handler doors/panels are securely secured.

An unsecured panel may trigger the safety switch, which stops power to the unit.

While it’s less common, an empty 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 below the current temperature. In the winter, verify it’s higher. This sounds goofy, but we’ve seen it happen many times.

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

Equipment still won’t turn on? Verify circuit breakers haven’t flipped and that your HVAC system isn’t showing error codes.

“Cool On” or “Heat On” is Flickering

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

Then, make sure it’s calling for the appropriate system to turn on. This is often demonstrated by “cool on,” “heat on” or an icon.

If these words or the picture is flashing, your thermostat is in a five-minute delay state. This feature protects your unit from damaging short cycling. This can occur if you lose electricity.

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 take place.
  • 173—Thermostat temperature sensor error. Call Lyric technical support at 800-633-3991.
  • 175—AC power resumed. No action required.
  • 181/182—Put in a new air filter. Clear the display by hitting “dismiss” after adding a new filter.
  • 184—Install a new humidifier pad. Clear the screen by hitting “dismiss” after installing a clean pad filter.
  • 185—Replace dehumidifier filter. Clear the display by tapping “dismiss” after putting in a clean filter.
  • 187—Clean or put in a new ventilator filter. Clear the display by hitting “dismiss” after adding a clean filter.
  • 188/189—Replace UV bulb. Call Pardee Service Experts at 843-410-6103 for help.
  • 210—Register online for outside temperature. Get the Lyric app to do this step and ensure proper thermostat operation.
  • 388—Register online for remote access and exterior temperature. Use the Lyric app to complete 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 pick new Wi-Fi network.
  • 508—Wi-Fi not configured. Use 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 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 operate.
  • 173—Thermostat temperature sensor error. Reach Pardee Service Experts at 843-410-6103 for support.
  • 175—AC power restored. 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 add a new water filter. Clear the monitor by hitting “dismiss” after completing these procedures.
  • 184—Install a new humidifier pad. Clear the thermostat by tapping “dismiss” after adding a new pad filter.
  • 185—Get a new dehumidifier filter. Clear the thermostat by tapping “dismiss” after installing a fresh filter.
  • 186—Wash ventilator core. Clear the thermostat by hitting “dismiss” after completing 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. Reach Pardee Service Experts at 843-410-6103 for assistance.
  • 210—Register online for outdoor temperature. Get the Lyric app to do this step and ensure accurate thermostat operation.
  • 388—Register online for remote access and exterior temperature. Download 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 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 trying the troubleshooting process, our pros are available to help. Give us a call at 843-410-6103 and we’ll be out as fast as we can to diagnose the malfunction.

If you use an aging thermostat, now is a fantastic time to consider a new thermostat. 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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