How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the best thermostat producers, and we proudly install them on a frequent basis in the U.S.. They’re durable and dependable. Also, Honeywell is frequently enhancing its technology, resulting in more features for your home.

Nevertheless, every thermostat can have errors occasionally. As a result, we’ve put together this helpful guidebook to go over troubleshooting. While Honeywell thermostat troubleshooting problems are rare, they happen.

While you can typically fix most thermostat troubles by yourself, they often need Expert assistance. Our HVAC Experts are here to support you when you need us. We’re only a call away at 866-397-3787.

Let’s get started with the process by finding out what type of thermostat your house has.

What Model 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 reducing utility bills.
    • Programmable—This thermostat has a digital screen and arrows you touch to set your desired temperature. You can also set daily programs to reduce the temperature when you’re at work and increase it when you return.
    • Smart—You won’t have to make any programs on this thermostat, since it learns your day. It instinctively raises and lowers the temperature when you or family members are away to help you save on heating and cooling bills. You can also raise or lower the temperature anywhere using your phone or other Wi-Fi-enabled device.

As you know many technologically advanced solutions, there are several malfunctions that can take place. The majority of of these problems don’t call for pro assistance and are simple to solve on your own.

Common Honeywell Thermostat Troubleshooting Problems

Every Honeywell thermostat has a unique kind of codes matching the problems that happen.

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

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

Display is Blank

If the monitor is blank on your programmable thermostat, you could need to put in new batteries. If that doesn’t fix the issue or you rely on a smart thermostat, there might be a wiring problem.

Next, you should make sure the power is enabled for your furnace or air handler. Verify the switch by the indoor equipment is switched “on”.

Additionally, you should confirm all furnace cabinet or air handler doors/panels are sturdily in place.

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

Less frequently, an empty screen can mean you should buy a new thermostat.

Heating and Cooling System Won’t Turn On

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

When it’s hot, verify you put the thermostat beneath the room temperature. When it’s cool, verify it’s higher. This sounds absurd, but we’ve seen it happen many times.

Confirm the power switch close to your indoor unit is in the “on” position. You should also make sure the cabinet doors or panels are secure on your furnace cabinet or air handler. A loose panel can activate the safety switch, stopping electricity to the equipment.

Unit still won’t run? Confirm circuit breakers haven’t tripped and that your HVAC unit isn’t showing error codes.

“Cool On” or “Heat On” is Blinking

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

Then, check it’s telling the correct equipment to run. This is often demonstrated by “cool on,” “heat on” or an icon.

If these words or the picture is flashing, your thermostat is in a five-minute delay mode. This setting protects your system from bad short cycling. This may happen if your power is interrupted.

Honeywell Thermostat-Specific Error Codes

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

    • 164—Heat pump needs service. Call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for help.
    • 168—Wi-Fi radio error. Call Lyric technical support at 800-633-3991. 170—Internal memory error. Contact Lyric technical support at 800-633-3991.
    • 171—Set date and time. Finish these settings so scheduling can run.
    • 173—Thermostat temperature sensor error. Reach 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 installing a new filter.
    • 184—Put in a new humidifier pad. Clear the display by hitting “dismiss” after installing a fresh pad filter.
    • 185—Replace dehumidifier filter. Clear the thermostat by tapping “dismiss” after installing a new filter.
    • 187—Clean or install a new ventilator filter. Clear the screen by tapping “dismiss” after putting in a new filter.
    • 188/189—Get a new UV bulb. Call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for assistance.
    • 210—Register online for outside temperature. Download the Lyric app to finish this step and ensure proper thermostat operation.
    • 388—Register online for remote access and outside temperature. Use the Lyric app to complete this step and ensure accurate thermostat operation.
    • 399—No Internet. Verify 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. Use the Lyric app and follow the steps to configure your thermostat.

For more information, look at this thermostat’s user manual.

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005)

    • 164—Heat pump needs service. Reach Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for help.
    • 168—Wi-Fi radio error. Call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for support.
    • 170—Internal memory error. Contact Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for assistance.
    • 171—Set date and time. Complete these settings so scheduling can operate.
    • 173—Thermostat temperature sensor error. Reach Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for support.
    • 175—AC power resumed. No action required.
    • 177—Indoor temperature sensor error. Call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for assistance.
    • 178—Outdoor temperature sensor error. Contact Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for help.
    • 181/182—Replace air filter. Clear the monitor by touching “dismiss” after adding a fresh filter.
    • 183—Rinse humidifier tank and install a new water filter. Clear the monitor by hitting “dismiss” after doing these procedures.
    • 184—Get a new humidifier pad. Clear the screen by touching “dismiss” after installing pad filter.
    • 185—Get a new dehumidifier filter. Clear the thermostat by hitting “dismiss” after installing a fresh filter.
    • 186—Rinse ventilator core. Clear the screen by touching “dismiss” after finishing this task.
    • 187—Rinse or get a new ventilator filter. Clear the screen by tapping “dismiss” after buying a new filter.
    • 188/189—Add a new UV bulb. Contact Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for assistance.
    • 210—Register online for outdoor temperature. Download the Lyric app to finish this step and ensure proper thermostat operation.
    • 388—Register online for remote access and outside temperature. Get the Lyric app to complete 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 configured. Download the Lyric app and follow the steps to connect your thermostat.

For more details, look at this thermostat’s user manual.

Our Experts are Ready to Help

If you’re still running into issues after going through the troubleshooting steps, our Experts are ready to assist you. Call us at 866-397-3787 and we’ll arrive rapidly to figure out the issue.

If you use a dated thermostat, right now is a great time to think about a new device. Thermostat technology has come a long way over the last few years. Ask us for more details on how smart thermostats can make your home better while helping save on energy expenses year-round.

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