How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the leading thermostat brands, and we proudly install them on a usual basis in the U.S.. They’re long-lasting and trustworthy. In addition, Honeywell is frequently advancing its technology, resulting in more features for your family.

Nevertheless, all thermostats can experience issues now and again. Due to this, we’ve compiled this helpful manual to walk you through troubleshooting. While Honeywell thermostat troubleshooting problems are rare, they do occur.

While you can usually repair the majority of thermostat issues alone, they often call for Expert support. Our home comfort pros are here to help when you need us. We’re only a call away at 866-397-3787.

Let’s begin the process by figuring out what model of thermostat your residence 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 type, but it’s also the least efficient for reducing utility costs.
    • 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 gone and increase it when you get back.
    • Smart—You won’t have to make any programs on this thermostat, since it picks up on your day. It automatically adjusts the temperature when you or loved ones are away to help you save on utility costs. You can also raise or lower the temperature anywhere on your phone or other Wi-Fi-enabled device.

As is the case with the majority of technologically advanced products, there are common glitches that might occur. Most of these problems don’t require Expert assistance and are simple to fix on your own.

Common Honeywell Thermostat Troubleshooting Problems

Each Honeywell thermostat has a special group of codes that correspond to the issues that occur.

Think how uncomplicated it can be to fix a computer by restarting it. Many times, correcting a thermostat can be just as uncomplicated.

Here are some of the most common Honeywell thermostat errors. These involve the following programmable thermostats:

Display is Blank

If the screen is blank on your programmable thermostat, you could need to install new batteries. If that doesn’t solve the trouble or you rely on a smart thermostat, there could be a wiring malfunction.

Next, you should ensure the power is enabled for your furnace or air handler. Confirm the switch near the indoor unit is switched “up”.

Additionally, you should make certain all furnace cabinet or air handler doors/panels are tightly secured.

An unsecured panel may trip the safety switch, which disconnects power to the unit.

Infrequently, an empty monitor could mean you should install a new thermostat.

Comfort System Won’t Turn On

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

In the summer, confirm you set the thermostat lower than the room temperature. In the winter, verify it’s higher. This sounds silly, but we’ve seen it take place lots of times.

Confirm the power switch close to your indoor equipment is in the “on” position. You should also comfirm the cabinet doors or panels are tight on your furnace cabinet or air handler. An open panel can trigger the safety switch, stopping power to the system.

Unit still won’t turn on? Verify circuit breakers haven’t flipped and that your HVAC system isn’t showing error codes.

“Cool On” or “Heat On” is Flickering

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

Then, verify it’s telling the right system to turn on. This is typically shown by “cool on,” “heat on” or an icon.

If these words or the picture is pulsing, your thermostat is in a five-minute delay status. This feature protects your system from harmful short cycling. This may take place if you lose power.

Honeywell Thermostat-Specific Error Codes

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

    • 164—Heat pump requires service. Call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 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. Finish these settings so scheduling can take place.
    • 173—Thermostat temperature sensor error. Contact Lyric technical support at 800-633-3991.
    • 175—AC power restored. No action needed.
    • 181/182—Replace air filter. Clear the monitor by hitting “dismiss” after adding a new filter.
    • 184—Install a new humidifier pad. Clear the screen by touching “dismiss” after adding a clean pad filter.
    • 185—Replace dehumidifier filter. Clear the screen by touching “dismiss” after putting in a new filter.
    • 187—Rinse or put in a new ventilator filter. Clear the display by hitting “dismiss” after installing a clean filter.
    • 188/189—Get a new UV bulb. Contact Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for support.
    • 210—Register online for outdoor temperature. Download the Lyric app to do this step and ensure correct thermostat operation.
    • 388—Register online for remote access and outdoor temperature. Use the Lyric app to do 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 select new Wi-Fi network.
    • 508—Wi-Fi not set. Download the Lyric app and follow the steps to connect your thermostat.

For more specifics, check 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 & Plumbing at 866-397-3787 for assistance.
    • 168—Wi-Fi radio error. Contact Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for help.
    • 170—Internal memory error. Call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for assistance.
    • 171—Set date and time. Finish these settings so scheduling can run.
    • 173—Thermostat temperature sensor error. Contact Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for support.
    • 175—AC power reconnected. No action required.
    • 177—Indoor temperature sensor error. Contact Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for support.
    • 178—Outdoor temperature sensor error. Contact Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for support.
    • 181/182—Replace air filter. Clear the thermostat by hitting “dismiss” after installing a clean filter.
    • 183—Clean humidifier tank and replace water filter. Clear the monitor by tapping “dismiss” after doing these procedures.
    • 184—Install a new humidifier pad. Clear the thermostat by hitting “dismiss” after getting a new pad filter.
    • 185—Install a new dehumidifier filter. Clear the screen by tapping “dismiss” after adding a fresh filter.
    • 186—Wash ventilator core. Clear the thermostat by tapping “dismiss” after completing this task.
    • 187—Clean or get a new ventilator filter. Clear the screen by hitting “dismiss” after buying a new filter.
    • 188/189—Get a new UV bulb. Contact Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for assistance.
    • 210—Register online for outside temperature. Get the Lyric app to finish this step and ensure proper thermostat operation.
    • 388—Register online for remote access and exterior temperature. Download the Lyric app to complete 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 select new Wi-Fi network.
    • 508—Wi-Fi not connected. Get the Lyric app and follow the procedures to connect your thermostat.

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

Our Experts are Ready to Provide Assistance

If you’re still experiencing issues after going through the troubleshooting process, our Experts are here to support you. Call us at 866-397-3787 and we’ll come to your house rapidly to figure out the malfunction.

If you use an older thermostat, now is a fantastic time to think about a replacement. Thermostat technology has gotten better over the last few years. Ask us for more info on how smart thermostats can make your house better while helping save on heating and cooling expenses throughout the year.

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