How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the top thermostat manufacturers, and we proudly install them on a usual basis in Birmingham. They’re durable and dependable. Plus, Honeywell is frequently advancing its technology, bringing more features for your home.

However, every thermostat can run into troubles occasionally. As a result, we’ve put together this helpful guide to go over troubleshooting.

While you can typically fix most thermostat issues alone, they occasionally need Expert help. Our heating and cooling Experts are ready to assist you when you need us. We’re only a call away at 205-267-0023.

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

What Type of Thermostat Do I Have?

There are three kinds of thermostats:

  • Manual—This is the older dial-shaped thermostat. You won’t run into error codes with this type, but it’s also the least efficient for lowering heating and cooling bills.
  • Programmable—This thermostat has a digital screen and arrows you use to determine your desired temperature. You can also set daily programs to lower the temperature when you’re away and raise it when you get back.
  • Smart—You won’t have to set any programs on this thermostat, since it adjusts to your routine. It instinctively adjusts the temperature when you or family members are out and about to help you save on utility expenses. 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 several malfunctions that can happen. The majority of of these issues don’t call for professional support and are easy to fix on your own.

Common Honeywell Thermostat Problems

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

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

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

Display is Blank

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

Next, you should ensure the power is on for your furnace or air handler. Make sure the switch by 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 tightly secured.

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

While it’s less common, a clear monitor may indicate you will need to buy a new thermostat.

Heating and Cooling System Won’t Start

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

When it’s hot, make sure you put the thermostat below the room temperature. When it’s cool, confirm it’s higher. This sounds silly, but we’ve seen it take place lots of times.

Ensure the power switch by your indoor system is in the “on” position. You should also check the cabinet doors or panels are tight on your furnace cabinet or air handler. An unsecured panel can trigger the safety switch, stopping electricity to the system.

Heating or cooling still won’t start? Verify circuit breakers haven’t turned off and that your HVAC system isn’t displaying error codes.

“Cool On” or “Heat On” is Blinking

To start, verify your thermostat is on “cool” or “heat.”

Then, check it’s telling the right equipment to start. This is usually shown by “cool on,” “heat on” or an illustration.

If these words or the illustration is blinking, your thermostat is in a five-minute delay mode. This setting keeps your equipment from harmful short cycling. This may take place if you lose electricity.

Honeywell Thermostat-Specific Error Codes

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

  • 164—Heat pump requires service. Call Norrell Service Experts at 205-267-0023 for help.
  • 168—Wi-Fi radio error. Call 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 run.
  • 173—Thermostat temperature sensor error. Contact Lyric technical support at 800-633-3991.
  • 175—AC power restarted. No action needed.
  • 181/182—Put in a new air filter. Clear the monitor by hitting “dismiss” after putting in a new filter.
  • 184—Replace humidifier pad. Clear the display by hitting “dismiss” after adding a new pad filter.
  • 185—Install a new dehumidifier filter. Clear the screen by touching “dismiss” after adding a clean filter.
  • 187—Wash or replace ventilator filter. Clear the thermostat by hitting “dismiss” after putting in a fresh filter.
  • 188/189—Get a new UV bulb. Ring Norrell Service Experts at 205-267-0023 for help.
  • 210—Register online for outdoor temperature. Get the Lyric app to do 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 proper thermostat operation.
  • 399—No Internet. Confirm 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. Use the Lyric app and follow the process to link your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump needs service. Call Norrell Service Experts at 205-267-0023 for help.
  • 168—Wi-Fi radio error. Contact Norrell Service Experts at 205-267-0023 for help.
  • 170—Internal memory error. Contact Norrell Service Experts at 205-267-0023 for help.
  • 171—Set date and time. Finalize these settings so scheduling can operate.
  • 173—Thermostat temperature sensor error. Call Norrell Service Experts at 205-267-0023 for support.
  • 175—AC power restored. No action needed.
  • 177—Indoor temperature sensor error. Call Norrell Service Experts at 205-267-0023 for assistance.
  • 178—Outdoor temperature sensor error. Call Norrell Service Experts at 205-267-0023 for assistance.
  • 181/182—Install a new air filter. Clear the monitor by hitting “dismiss” after putting in a new filter.
  • 183—Wash humidifier tank and install a new water filter. Clear the screen by hitting “dismiss” after doing these steps.
  • 184—Get a new humidifier pad. Clear the display by hitting “dismiss” after adding a new pad filter.
  • 185—Replace dehumidifier filter. Clear the screen by touching “dismiss” after adding a clean filter.
  • 186—Clean ventilator core. Clear the thermostat by hitting “dismiss” after finishing this task.
  • 187—Rinse or install a new ventilator filter. Clear the display by hitting “dismiss” after getting a new filter.
  • 188/189—Get a new UV bulb. Contact Norrell Service Experts at 205-267-0023 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. Get the Lyric app to complete this step and ensure proper 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 set up. Get the Lyric app and follow the procedures to connect your thermostat.

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

Our Experts are Available to Help

If you’re still running into troubles after going through the troubleshooting list, our professionals are ready to assist you. Give us a call at 205-267-0023 and we’ll come to your house as fast as we can to determine the issue.

If you rely on an aging thermostat, right now is a fantastic time to think about a replacement. Thermostat technology has advanced in recent years Ask us for more info on how smart thermostats can make your house more convenient while helping save on energy costs year-round.

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