How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the best thermostat brands, and we proudly install them on a frequent basis in West Palm Beach. They’re long-lasting and reliable. Plus, Honeywell is frequently updating its technology, offering more features for your residence.

Still, every thermostat can have troubles now and again. Due to this, we’ve prepared this informative manual to go over troubleshooting.

While you can often fix most thermostat issues by yourself, they sometimes call for Expert assistance. Our HVAC Experts are ready to assist you when you need us. We’re just a call away at 561-629-1826.

Let’s start the process by finding out what kind of thermostat your home has.

What Model of Thermostat Do I Have?

There are three kinds of thermostats:

  • Manual—This is the typical dial-shaped thermostat. You won’t experience error codes with this one, but it’s also the least efficient for reducing heating and cooling expenses.
  • Programmable—This thermostat includes a digital screen and arrows you use to choose your desired temperature. You can also choose daily programs to decrease the temperature when you’re at work and increase it when you return.
  • Smart—You won’t have to schedule any programs on this thermostat, as it learns your schedule. It automatically changes the temperature when you or loved ones are out and about to help you save on heating and cooling costs. You can also raise or lower the temperature anywhere using your phone or other Wi-Fi-enabled device. 

As you know many technologically advanced products, there are regular problems that may happen. Many of these issues don’t require pro support and are easy to solve on your own.

Common Honeywell Thermostat Troubles

Every thermostat has a unique set of codes matching the malfunctions that occur.

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

Here is a guide to the most reported Honeywell thermostat errors. These include the following programmable thermostats:

Display is Blank

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

Next, you should check the power is on for your furnace or air handler. Verify the switch near the indoor equipment is in the “on” position.

In addition to that, you should make certain all furnace cabinet or air handler doors/panels are securely in place.

A panel that isn’t tight may activate the safety switch, which cuts off power to the equipment.

Infrequently, a clear screen may mean you should install a new thermostat.

HVAC Unit Won’t Start

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

In the summer, make sure you put the thermostat beneath the room temperature. When it’s cold, verify it’s higher. This sounds silly, but we’ve seen it take place many times.

Make sure the power switch close to your indoor equipment is in the “on” position. You should also check the cabinet doors or panels are closed on your furnace cabinet or air handler. An open panel can trip the safety switch, stopping power to the system.

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

“Cool On” or “Heat On” is Flickering

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

Then, make sure it’s telling the right system to start. This is typically shown by “cool on,” “heat on” or a picture.

If this phrase or the illustration is flashing, your thermostat is in a five-minute delay status. This mode stops your equipment from bad short cycling. This could happen if you lose power.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump needs service. Call Service Experts Heating & Air Conditioning at 561-629-1826 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. 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 display by tapping “dismiss” after adding a new filter.
  • 184—Install a new humidifier pad. Clear the screen by tapping “dismiss” after adding a fresh pad filter.
  • 185—Put in a new dehumidifier filter. Clear the thermostat by tapping “dismiss” after putting in a fresh filter.
  • 187—Wash or replace ventilator filter. Clear the screen by hitting “dismiss” after putting in a clean filter.
  • 188/189—Replace UV bulb. Call Service Experts Heating & Air Conditioning at 561-629-1826 for support.
  • 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. Get the Lyric app to do this step and ensure correct thermostat operation.
  • 399—No Internet. Check 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. Download the Lyric app and follow the process to configure your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump must be serviced service. Contact Service Experts Heating & Air Conditioning at 561-629-1826 for support.
  • 168—Wi-Fi radio error. Reach Service Experts Heating & Air Conditioning at 561-629-1826 for help.
  • 170—Internal memory error. Contact Service Experts Heating & Air Conditioning at 561-629-1826 for assistance.
  • 171—Set date and time. Complete these settings so scheduling can run.
  • 173—Thermostat temperature sensor error. Reach Service Experts Heating & Air Conditioning at 561-629-1826 for help.
  • 175—AC power reconnected. No action necessary.
  • 177—Indoor temperature sensor error. Call Service Experts Heating & Air Conditioning at 561-629-1826 for help.
  • 178—Outdoor temperature sensor error. Reach Service Experts Heating & Air Conditioning at 561-629-1826 for assistance.
  • 181/182—Replace air filter. Clear the screen by tapping “dismiss” after installing a clean filter.
  • 183—Clean humidifier tank and install a new water filter. Clear the monitor by hitting “dismiss” after completing these steps.
  • 184—Get a new humidifier pad. Clear the thermostat by touching “dismiss” after installing pad filter.
  • 185—Install a new dehumidifier filter. Clear the thermostat by hitting “dismiss” after adding a fresh filter.
  • 186—Rinse ventilator core. Clear the display by hitting “dismiss” after doing this task.
  • 187—Wash or get a new ventilator filter. Clear the monitor by hitting “dismiss” after buying a new filter.
  • 188/189—Install a new UV bulb. Contact Service Experts Heating & Air Conditioning at 561-629-1826 for help.
  • 210—Register online for outdoor temperature. Download the Lyric app to do this step and ensure proper thermostat operation.
  • 388—Register online for remote access and outdoor temperature. Download the Lyric app to do 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 connected. Download the Lyric app and follow the process to connect your thermostat.

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

Our Experts are Here to Provide Support

If you’re still experiencing problems after trying the troubleshooting list, our professionals are here to help. Give us a call at 561-629-1826 and we’ll arrive quickly to determine the problem.

If you use an older thermostat, right now is a good time to consider a replacement. Thermostat technology has come a long way lately Ask us for more info on how smart thermostats can make your home more comfortable while helping save on utility bills all year.

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