How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the best thermostat manufacturers, and we proudly install them on a frequent basis in Dallas. They’re durable and reliable. Plus, Honeywell is constantly enhancing its technology, offering more features for your household.

However, every thermostat can experience errors every now and then. Due to this, we’ve put together this useful handbook to go over troubleshooting.

While you can often solve many thermostat problems by yourself, they often call for Expert assistance. Our HVAC professionals are ready to help when you need us. We’re only a call away at 469-250-0932.

Let’s begin the process by determining 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 one, but it’s also the least efficient for reducing heating and cooling bills.
  • Programmable—This thermostat includes a digital screen and arrows you press to choose your desired temperature. You can also choose daily programs to lower the temperature when you’re away and set it higher when you return.
  • Smart—You won’t have to set any programs on this thermostat, since it picks up on your routine. It automatically adjusts the temperature when you or other household members are out and about to help you save on energy expenses. You can also adjust the temperature anywhere using your phone or other Wi-Fi-enabled device. 

As you’re aware the majority of technologically advanced solutions, there are common glitches that can take place. Most of these issues don’t call for pro assistance and are simple to repair alone.

Common Honeywell Thermostat Issues

Every thermostat has a unique set of codes assigned to the malfunctions that happen.

Think how uncomplicated it can be to restore a computer by restarting it. Many times, diagnosing a thermostat can be just as easy.

Here are some of the most encountered Honeywell thermostat errors. These are applicable to the following programmable thermostats:

Display is Blank

If the monitor is empty on your programmable thermostat, you could need to get new batteries. If that doesn’t solve the issue or you have a smart thermostat, there may be a wiring malfunction.

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

Also, you should make certain all furnace cabinet or air handler doors/panels are sturdily in place.

A panel that isn’t tight may trip the safety switch, which disconnects power to the unit.

Infrequently, a blank monitor can mean you need to get a new thermostat.

HVAC System Won’t Turn On

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

When it’s hot, confirm you schedule the thermostat lower than the current temperature. When it’s cool, make sure it’s higher. This sounds goofy, but we’ve seen it take place lots of 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. A loose panel can activate the safety switch, cutting off electricity to the system.

Unit still won’t turn on? Confirm circuit breakers haven’t tripped and that your HVAC equipment isn’t experiencing error codes.

“Cool On” or “Heat On” is Flickering

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

Then, make sure it’s signaling the appropriate unit to turn on. This is usually indicated by “cool on,” “heat on” or an illustration.

If this set of words or the icon is pulsing, your thermostat is in a five-minute delay mode. This feature stops your system from harmful short cycling. This may occur if you lose electricity.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump requires service. Call Levy & Son Service Experts at 469-250-0932 for support.
  • 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. Complete these settings so scheduling can run.
  • 173—Thermostat temperature sensor error. Reach 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 tapping “dismiss” after adding a fresh filter.
  • 184—Install a new humidifier pad. Clear the thermostat by tapping “dismiss” after putting in a clean pad filter.
  • 185—Put in a new dehumidifier filter. Clear the screen by touching “dismiss” after installing a fresh filter.
  • 187—Wash or replace ventilator filter. Clear the display by tapping “dismiss” after installing a fresh filter.
  • 188/189—Replace UV bulb. Call Levy & Son Service Experts at 469-250-0932 for support.
  • 210—Register online for exterior temperature. Download the Lyric app to do 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 choose new Wi-Fi network.
  • 508—Wi-Fi not set up. Use the Lyric app and follow the process to link 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 Levy & Son Service Experts at 469-250-0932 for support.
  • 168—Wi-Fi radio error. Reach Levy & Son Service Experts at 469-250-0932 for support.
  • 170—Internal memory error. Contact Levy & Son Service Experts at 469-250-0932 for assistance.
  • 171—Set date and time. Finalize these settings so scheduling can operate.
  • 173—Thermostat temperature sensor error. Contact Levy & Son Service Experts at 469-250-0932 for help.
  • 175—AC power reconnected. No action required.
  • 177—Indoor temperature sensor error. Reach Levy & Son Service Experts at 469-250-0932 for support.
  • 178—Outdoor temperature sensor error. Call Levy & Son Service Experts at 469-250-0932 for assistance.
  • 181/182—Get a new air filter. Clear the screen by touching “dismiss” after installing a new filter.
  • 183—Rinse humidifier tank and add a new water filter. Clear the screen by tapping “dismiss” after finishing these procedures.
  • 184—Get a new humidifier pad. Clear the screen by touching “dismiss” after getting a new pad filter.
  • 185—Replace dehumidifier filter. Clear the thermostat by hitting “dismiss” after installing a fresh filter.
  • 186—Rinse ventilator core. Clear the display by touching “dismiss” after finishing this task.
  • 187—Wash or get a new ventilator filter. Clear the monitor by touching “dismiss” after buying a new filter.
  • 188/189—Add a new UV bulb. Reach Levy & Son Service Experts at 469-250-0932 for help.
  • 210—Register online for outside temperature. Get the Lyric app to complete this step and ensure accurate thermostat operation.
  • 388—Register online for remote access and exterior temperature. Download the Lyric app to complete 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 select new Wi-Fi network.
  • 508—Wi-Fi not set up. Use the Lyric app and follow the steps to connect your thermostat.

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

Our Experts are Ready to Provide Assistance

If you’re still having issues after trying the troubleshooting list, our pros are ready to help. Call us at 469-250-0932 and we’ll come to your house quickly to determine the issue.

If you have an aging thermostat, today is a great time to think about a new thermostat. Thermostat technology has gotten better over the last few years. Ask us for more details on how smart thermostats can make your home comfier while helping save on heating and cooling bills year-round.

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