How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the leading thermostat manufacturers, and we proudly install them on a frequent basis in Columbia. They’re durable and reliable. In addition, Honeywell is frequently improving its technology, resulting in more features for your household.

Nevertheless, all thermostats can run into errors from time to time. Due to this, we’ve put together this valuable guidebook to go over troubleshooting.

While you can usually solve most thermostat troubles on your own, they sometimes require Expert help. Our home comfort pros are ready to assist you when you need us. We’re merely a call away at 803-399-7208.

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

What Type of Thermostat Do I Have?

There are three kinds of thermostats:

  • Manual—This is the classic dial-shaped thermostat. You won’t have error codes with this kind, but it’s also the least efficient for lowering heating and cooling bills.
  • Programmable—This thermostat features a digital screen and arrows you press to determine your desired temperature. You can also set daily programs to reduce the temperature when you’re at work and raise it when you get back.
  • Smart—You won’t have to schedule any programs on this thermostat, because it picks up on your schedule. It intuitively adjusts the temperature when you or family members are out and about to help you save on heating and cooling expenses. You can also change the temperature anywhere via your phone or other Wi-Fi-enabled device. 

As is the case with most technologically advanced things, there are several malfunctions that can occur. Most of these issues don’t call for professional help and are simple to repair alone.

Common Honeywell Thermostat Troubles

Every thermostat has an exclusive kind of codes that correspond to the troubles that happen.

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

Here is a guide to the most reported Honeywell thermostat problems. These are applicable to the following programmable thermostats:

Display is Blank

If the display is clear on your programmable thermostat, you might need to get new batteries. If that doesn’t solve the malfunction or you rely on a smart thermostat, there could 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 switched “up”.

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

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

Infrequently, a clear screen could mean you will need to get a new thermostat.

HVAC Unit Won’t Work

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

During warm weather, confirm you put the thermostat beneath the ambient temperature. In the winter, verify it’s higher. This sounds absurd, but we’ve seen it occur many times.

Make sure the power switch near your indoor system 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 trigger the safety switch, diverting power to the equipment.

Equipment still won’t start? Make sure circuit breakers haven’t tripped and that your HVAC equipment isn’t experiencing error codes.

“Cool On” or “Heat On” is Flashing

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

Then, verify it’s calling for the appropriate equipment to turn on. This is usually demonstrated by “cool on,” “heat on” or an illustration.

If this set of words or the illustration is pulsing, your thermostat is in a five-minute delay state. This mode stops your unit from bad short cycling. This can happen if you lose electricity.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump needs service. Call Midland Air Service Experts at 803-399-7208 for support.
  • 168—Wi-Fi radio error. Reach Lyric technical support at 800-633-3991. 170—Internal memory error. Reach 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 restored. No action necessary.
  • 181/182—Replace air filter. Clear the display by tapping “dismiss” after installing a new filter.
  • 184—Install a new humidifier pad. Clear the screen by touching “dismiss” after putting in a new pad filter.
  • 185—Install a new dehumidifier filter. Clear the thermostat by touching “dismiss” after installing a new filter.
  • 187—Wash or install a new ventilator filter. Clear the screen by tapping “dismiss” after adding a new filter.
  • 188/189—Replace UV bulb. Ring Midland Air Service Experts at 803-399-7208 for assistance.
  • 210—Register online for exterior temperature. Use the Lyric app to finish this step and ensure correct thermostat operation.
  • 388—Register online for remote access and exterior temperature. Download the Lyric app to do 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 select new Wi-Fi network.
  • 508—Wi-Fi not set. Download the Lyric app and follow the procedure to link your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump must be serviced service. Contact Midland Air Service Experts at 803-399-7208 for assistance.
  • 168—Wi-Fi radio error. Reach Midland Air Service Experts at 803-399-7208 for assistance.
  • 170—Internal memory error. Call Midland Air Service Experts at 803-399-7208 for assistance.
  • 171—Set date and time. Finalize these settings so scheduling can work.
  • 173—Thermostat temperature sensor error. Reach Midland Air Service Experts at 803-399-7208 for assistance.
  • 175—AC power restored. No action necessary.
  • 177—Indoor temperature sensor error. Call Midland Air Service Experts at 803-399-7208 for assistance.
  • 178—Outdoor temperature sensor error. Reach Midland Air Service Experts at 803-399-7208 for assistance.
  • 181/182—Get a new air filter. Clear the display by touching “dismiss” after installing a fresh filter.
  • 183—Wash humidifier tank and add a new water filter. Clear the display by touching “dismiss” after doing these procedures.
  • 184—Replace humidifier pad. Clear the thermostat by touching “dismiss” after getting a new pad filter.
  • 185—Replace dehumidifier filter. Clear the thermostat by tapping “dismiss” after installing a fresh filter.
  • 186—Wash ventilator core. Clear the monitor by hitting “dismiss” after doing this task.
  • 187—Wash or install a new ventilator filter. Clear the screen by touching “dismiss” after buying a new filter.
  • 188/189—Get a new UV bulb. Contact Midland Air Service Experts at 803-399-7208 for assistance.
  • 210—Register online for outside temperature. Use the Lyric app to finish this step and ensure proper thermostat operation.
  • 388—Register online for remote access and exterior temperature. Use the Lyric app to do 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 choose new Wi-Fi network.
  • 508—Wi-Fi not configured. Download the Lyric app and follow the procedures to connect your thermostat.

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

Our Experts are Ready to Help

If you’re still experiencing troubles after trying the troubleshooting steps, our professionals are ready to support you. Call us at 803-399-7208 and we’ll come to your house rapidly to diagnose the problem.

If you rely on an older thermostat, now is a fantastic time to think about a new device. Thermostat technology has come a long way in recent years Ask us for more details on how smart thermostats can make your residence more convenient while helping save on energy costs throughout the year.

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