How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the best thermostat producers, and we proudly install them on a regular basis in London. They’re long-lasting and dependable. In addition, Honeywell is frequently enhancing its technology, resulting in more features for your household.

Nevertheless, each thermostat can have troubles once in awhile. Due to this, we’ve prepared this informative guidebook to go over troubleshooting.

While you can often repair many thermostat troubles by yourself, they occasionally call for Expert help. Our heating and cooling pros are ready to assist you when you need us. We’re merely a call away at 226-270-1164.

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

What Kind of Thermostat Do I Have?

There are three types of thermostats:

  • Manual—This is the classic dial-shaped thermostat. You won’t run into error codes with this one, but it’s also the least efficient for saving on utility bills.
  • Programmable—This thermostat has 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 set it higher when you get back.
  • Smart—You won’t have to make any programs on this thermostat, since it picks up on 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 via your phone or other Wi-Fi-enabled device. 

As you’re aware most technologically advanced products, there are common malfunctions that may take place. Most of these problems don’t call for pro support and are uncomplicated enough to solve alone.

Common Honeywell Thermostat Problems

All thermostats have a unique set of codes assigned to the problems that take place.

Think how uncomplicated it can be to fix a computer by restarting it. Many times, correcting a thermostat can be just as simple.

Here is a guide to the most encountered Honeywell thermostat issues. These apply to the following programmable thermostats:

Display is Blank

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

Next, you should check the power is enabled for your furnace or air handler. Make sure the switch by the indoor equipment is in the “on” position.

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

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

Infrequently, an empty monitor could indicate you need to buy a new thermostat.

Comfort Unit Won’t Run

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

When it’s hot, make sure you set the thermostat lower than the current temperature. When it’s cool, verify it’s higher. This sounds goofy, but we’ve seen it happen a lot of times.

Ensure the power switch close to your indoor system 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 activate the safety switch, stopping power to the equipment.

Equipment still won’t run? Confirm circuit breakers haven’t flipped and that your HVAC equipment isn’t experiencing error codes.

“Cool On” or “Heat On” is Blinking

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

Then, check it’s signaling the appropriate system to run. This is usually 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 mode. This setting protects your system from bad short cycling. This could take place if your power is interrupted.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump needs service. Call Roy Inch & Sons Service Experts at 226-270-1164 for support.
  • 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 take place.
  • 173—Thermostat temperature sensor error. Reach Lyric technical support at 800-633-3991.
  • 175—AC power resumed. No action required.
  • 181/182—Replace air filter. Clear the thermostat by hitting “dismiss” after installing a clean filter.
  • 184—Replace humidifier pad. Clear the thermostat by hitting “dismiss” after adding a clean pad filter.
  • 185—Put in a new dehumidifier filter. Clear the monitor by tapping “dismiss” after adding a clean filter.
  • 187—Clean or install a new ventilator filter. Clear the monitor by touching “dismiss” after installing a new filter.
  • 188/189—Install a new UV bulb. Contact Roy Inch & Sons Service Experts at 226-270-1164 for assistance.
  • 210—Register online for outdoor temperature. Download the Lyric app to finish this step and ensure accurate thermostat operation.
  • 388—Register online for remote access and outdoor temperature. Download the Lyric app to finish this step and ensure proper thermostat operation.
  • 399—No Internet. Check 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. Get the Lyric app and follow the process to configure your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump needs service. Contact Roy Inch & Sons Service Experts at 226-270-1164 for assistance.
  • 168—Wi-Fi radio error. Call Roy Inch & Sons Service Experts at 226-270-1164 for support.
  • 170—Internal memory error. Call Roy Inch & Sons Service Experts at 226-270-1164 for assistance.
  • 171—Set date and time. Finalize these settings so scheduling can work.
  • 173—Thermostat temperature sensor error. Call Roy Inch & Sons Service Experts at 226-270-1164 for assistance.
  • 175—AC power resumed. No action needed.
  • 177—Indoor temperature sensor error. Contact Roy Inch & Sons Service Experts at 226-270-1164 for assistance.
  • 178—Outdoor temperature sensor error. Contact Roy Inch & Sons Service Experts at 226-270-1164 for help.
  • 181/182—Get a new air filter. Clear the display by tapping “dismiss” after adding a fresh filter.
  • 183—Rinse humidifier tank and install a new water filter. Clear the monitor by tapping “dismiss” after finishing these tasks.
  • 184—Get a new humidifier pad. Clear the display by touching “dismiss” after adding a new pad filter.
  • 185—Get a new dehumidifier filter. Clear the thermostat by tapping “dismiss” after putting in a clean filter.
  • 186—Wash ventilator core. Clear the monitor by hitting “dismiss” after completing this task.
  • 187—Wash or replace ventilator filter. Clear the display by tapping “dismiss” after getting a new filter.
  • 188/189—Add a new UV bulb. Reach Roy Inch & Sons Service Experts at 226-270-1164 for help.
  • 210—Register online for outdoor temperature. Get the Lyric app to complete 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 proper thermostat operation.
  • 399—No Internet. Check your network settings.
  • 400—No Wi-Fi signal. Wait for the thermostat to reconnect or choose new Wi-Fi network.
  • 508—Wi-Fi not connected. Download the Lyric app and follow the procedures to connect your thermostat.

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

Our Experts are Available to Help

If you’re still experiencing troubles after trying the troubleshooting process, our pros are here to assist you. Call us at 226-270-1164 and we’ll arrive quickly to diagnose the issue.

If you have an aging thermostat, now is a great time to think about a new device. Thermostat technology has come a long way lately Ask us for more details on how smart thermostats can make your home better while helping save on utility bills year-round.

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