How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the leading thermostat manufacturers, and we proudly install them on a usual basis in Wheeling. They’re durable and reliable. Also, Honeywell is frequently advancing its technology, bringing more features for your residence.

Nevertheless, every thermostat can have troubles occasionally. That’s why we’ve prepared this valuable manual to walk you through troubleshooting.

While you can typically solve the majority of thermostat problems on your own, they occasionally require Expert support. Our HVAC Experts are available to help when you need us. We’re just a call away at 847-250-6729.

Let’s begin the process by finding out what model of thermostat your home has.

What Model of Thermostat Do I Have?

There are three models of thermostats:

  • Manual—This is the older dial-shaped thermostat. You won’t experience error codes with this one, but it’s also the least efficient for lowering heating and cooling costs.
  • Programmable—This thermostat has a digital screen and arrows you use to set your desired temperature. You can also choose daily programs to decrease 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, as it picks up on your schedule. It intuitively changes the temperature when you or loved ones are away to help you save on utility bills. You can also raise or lower the temperature anywhere on your phone or other Wi-Fi-enabled device. 

As you know the majority of technologically advanced products, there are several glitches that might occur. The majority of of these issues don’t need pro help and are uncomplicated enough to repair by yourself.

Common Honeywell Thermostat Problems

Each thermostat has an exclusive set of codes that correspond to the glitches that take place.

Think how uncomplicated it can be to repair a computer by restarting it. In many instances, correcting a thermostat can be just as easy.

Here is a listing the most reported Honeywell thermostat problems. These include 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 take care of the malfunction or you use a smart thermostat, there could be a wiring problem.

Next, you should ensure the power is flowing for your furnace or air handler. Verify the switch close to the indoor equipment is switched “on”.

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

A panel that isn’t tight may trigger the safety switch, which stops power to the system.

Less frequently, a clear display may indicate you will need to get a new thermostat.

HVAC Unit Won’t Work

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

In the summer, make sure you set the thermostat lower than the room temperature. When it’s cool, make sure it’s higher. This sounds silly, but we’ve seen it take place a lot of times.

Confirm the power switch near your indoor unit is in the “on” position. You should also make sure the cabinet doors or panels are closed on your furnace cabinet or air handler. An open panel can activate the safety switch, stopping power to the equipment.

Unit still won’t run? Make sure circuit breakers haven’t tripped and that your HVAC system isn’t displaying error codes.

“Cool On” or “Heat On” is Flickering

First, verify your thermostat is switched to “cool” or “heat.”

Then, ensure it’s calling for the correct system to run. This is typically demonstrated by “cool on,” “heat on” or an illustration.

If this phrase or the icon is blinking, your thermostat is in a five-minute delay state. This setting protects your unit from damaging short cycling. This can take place if you lose power.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump needs service. Call Comfort Masters Service Experts at 847-250-6729 for assistance.
  • 168—Wi-Fi radio error. Contact 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. Call Lyric technical support at 800-633-3991.
  • 175—AC power restored. No action necessary.
  • 181/182—Replace air filter. Clear the display by tapping “dismiss” after installing a new filter.
  • 184—Put in a new humidifier pad. Clear the monitor by touching “dismiss” after adding a new pad filter.
  • 185—Put in a new dehumidifier filter. Clear the thermostat by touching “dismiss” after putting in a clean filter.
  • 187—Clean or replace ventilator filter. Clear the thermostat by touching “dismiss” after adding a clean filter.
  • 188/189—Get a new UV bulb. Call Comfort Masters Service Experts at 847-250-6729 for help.
  • 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 exterior temperature. Get the Lyric app to finish this step and ensure accurate 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 set up. Use the Lyric app and follow the procedure to connect your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump needs service. Reach Comfort Masters Service Experts at 847-250-6729 for assistance.
  • 168—Wi-Fi radio error. Reach Comfort Masters Service Experts at 847-250-6729 for help.
  • 170—Internal memory error. Reach Comfort Masters Service Experts at 847-250-6729 for help.
  • 171—Set date and time. Finalize these settings so scheduling can operate.
  • 173—Thermostat temperature sensor error. Call Comfort Masters Service Experts at 847-250-6729 for assistance.
  • 175—AC power restored. No action required.
  • 177—Indoor temperature sensor error. Call Comfort Masters Service Experts at 847-250-6729 for help.
  • 178—Outdoor temperature sensor error. Call Comfort Masters Service Experts at 847-250-6729 for assistance.
  • 181/182—Replace air filter. Clear the display by hitting “dismiss” after putting in a clean filter.
  • 183—Clean humidifier tank and install a new water filter. Clear the screen by tapping “dismiss” after finishing these procedures.
  • 184—Get a new humidifier pad. Clear the display by tapping “dismiss” after getting a new pad filter.
  • 185—Install a new dehumidifier filter. Clear the thermostat by touching “dismiss” after putting in a new filter.
  • 186—Wash ventilator core. Clear the screen by hitting “dismiss” after completing this task.
  • 187—Wash or get a new ventilator filter. Clear the screen by touching “dismiss” after getting a new filter.
  • 188/189—Get a new UV bulb. Get in touch with Comfort Masters Service Experts at 847-250-6729 for support.
  • 210—Register online for outdoor temperature. Download the Lyric app to do this step and ensure correct thermostat operation.
  • 388—Register online for remote access and outside temperature. Get the Lyric app to complete this step and ensure accurate thermostat operation.
  • 399—No Internet. Confirm your network settings.
  • 400—No Wi-Fi signal. Wait for the thermostat to reconnect or pick new Wi-Fi network.
  • 508—Wi-Fi not set up. Download the Lyric app and follow the procedures to connect your thermostat.

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

Our Experts are Ready to Provide Assistance

If you’re still running into problems after going through the troubleshooting steps, our Experts are here to support you. Call us at 847-250-6729 and we’ll come to your house as fast as we can to figure out the issue.

If you rely on an aging thermostat, today is a great time to think over a new device. Thermostat technology has advanced over the last few years. Ask us for more information on how smart thermostats can make your house more convenient while helping save on energy bills year-round.

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