How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the best thermostat brands, and we proudly install them on a usual basis in the U.S.. They’re durable and dependable. Plus, Honeywell is regularly advancing its technology, offering more features for your family.

Nevertheless, each thermostat can have errors every so often. That’s why we’ve prepared this helpful guide to walk you through troubleshooting. While Honeywell thermostat troubleshooting problems are rare, they happen.

While you can usually repair most thermostat issues by yourself, they often need Expert assistance. Our home comfort pros are available to support you when you need us. We’re only a call away at 866-397-3787.

Let’s begin the process by finding out what kind of thermostat your residence has.

What Type of Thermostat Do I Have?

There are three models of thermostats:

    • Manual—This is the older dial-shaped thermostat. You won’t run into error codes with this kind, but it’s also the least efficient for saving on utility bills.
    • Programmable—This thermostat includes a digital screen and arrows you touch to choose your desired temperature. You can also use daily programs to decrease the temperature when you’re away and set it higher when you come home.
    • Smart—You won’t have to make any programs on this thermostat, since it picks up on your routine. It intuitively changes the temperature when you or other household members are gone to help you save on utility bills. You can also raise or lower the temperature anywhere on your phone or other Wi-Fi-enabled device.

As you know the majority of technologically advanced solutions, there are several problems that can take place. The majority of of these problems don’t need professional help and are simple to fix on your own.

Common Honeywell Thermostat Troubleshooting Errors

All Honeywell thermostats have a special group of codes that correspond to the malfunctions that occur.

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

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

Display is Blank

If the display is blank on your programmable thermostat, you might need to get new batteries. If that doesn’t fix the trouble or you rely on a smart thermostat, there may be a wiring problem.

Next, you should check the power is flowing for your furnace or air handler. Make sure the switch by the indoor equipment is switched “on”.

Additionally, 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 cuts off power to the unit.

Less frequently, an empty monitor might signify you will need to replace your thermostat.

Comfort Unit Won’t Run

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

When it’s hot, confirm you set the thermostat below the current temperature. In the winter, confirm it’s higher. This sounds silly, but we’ve seen it happen lots of times.

Confirm the power switch near your indoor system is in the “on” position. You should also make sure the cabinet doors or panels are secure on your furnace cabinet or air handler. An unsecured panel can trigger the safety switch, diverting power to the unit.

System still won’t turn on? Verify circuit breakers haven’t tripped and that your HVAC system isn’t displaying error codes.

“Cool On” or “Heat On” is Blinking

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

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

If this phrase or the icon is blinking, your thermostat is in a five-minute delay mode. This mode protects your unit from bad 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 must be serviced. Call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for assistance.
    • 168—Wi-Fi radio error. Call 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 run.
    • 173—Thermostat temperature sensor error. Call Lyric technical support at 800-633-3991.
    • 175—AC power restarted. No action required.
    • 181/182—Install a new air filter. Clear the screen by touching “dismiss” after putting in a fresh filter.
    • 184—Replace humidifier pad. Clear the monitor by touching “dismiss” after adding a fresh pad filter.
    • 185—Replace dehumidifier filter. Clear the display by tapping “dismiss” after putting in a clean filter.
    • 187—Wash or replace ventilator filter. Clear the screen by hitting “dismiss” after putting in a new filter.
    • 188/189—Replace UV bulb. Contact Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for support.
    • 210—Register online for outside temperature. Download the Lyric app to complete this step and ensure proper thermostat operation.
    • 388—Register online for remote access and outside temperature. Get the Lyric app to do this step and ensure correct 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 procedure to link your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005)

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

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

Our Experts are Available to Provide Support

If you’re still having problems after trying the troubleshooting steps, our Experts are ready to help. Call us at 866-397-3787 and we’ll arrive rapidly to figure out the issue.

If you rely on a dated thermostat, today is a great time to consider a new thermostat. Thermostat technology has come a long way in recent years Ask us for more details on how smart thermostats can make your home comfier while helping save on heating and cooling expenses all year.

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