How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the leading thermostat producers, and we proudly install them on a usual basis in the U.S.. They’re durable and dependable. Plus, Honeywell is regularly enhancing its technology, bringing more features for your residence.

Nevertheless, each thermostat can have problems from time to time. As a result, we’ve put together this useful handbook to go over troubleshooting. While Honeywell thermostat troubleshooting problems are rare, they happen.

While you can typically solve the majority of thermostat problems by yourself, they sometimes require Expert support. Our home comfort pros are here to help when you need us. We’re just a call away at 866-397-3787.

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

What Type of Thermostat Do I Have?

There are three models of thermostats:

    • Manual—This is the classic 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 includes a digital screen and arrows you touch to determine your desired temperature. You can also use daily programs to reduce the temperature when you’re away and increase it when you come home.
    • Smart—You won’t have to make any programs on this thermostat, as it learns your day. It instinctively adjusts the temperature when you or other household members are gone to help you save on heating and cooling expenses. You can also change the temperature anywhere on your phone or other Wi-Fi-enabled device.

As you know many technologically advanced things, there are regular glitches that can happen. Most of these issues don’t need Expert assistance and are uncomplicated enough to repair on your own.

Common Honeywell Thermostat Troubleshooting Errors

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

Think how simple it can be to restore a computer by restarting it. In many instances, troubleshooting a thermostat can be just as simple.

Here are some of 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 get new batteries. If that doesn’t fix the malfunction or you rely on a smart thermostat, there could be a wiring malfunction.

Next, you should ensure the power is flowing for your furnace or air handler. Make sure the switch near the indoor system is switched “up”.

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

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

Infrequently, a clear screen might indicate you need to buy a new thermostat.

Comfort System Won’t Turn On

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

During warm weather, verify you set the thermostat beneath the ambient temperature. When it’s cool, make sure it’s higher. This sounds absurd, but we’ve seen it happen lots of times.

Make sure the power switch near your indoor equipment is in the “on” position. You should also make sure the cabinet doors or panels are tight on your furnace cabinet or air handler. An unsecured panel can trip the safety switch, stopping current to the system.

Heating or cooling still won’t run? Confirm circuit breakers haven’t tripped and that your HVAC equipment isn’t experiencing error codes.

“Cool On” or “Heat On” is Flashing

To start, make sure your thermostat is switched to “cool” or “heat.”

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

If this set of words or the icon is blinking, your thermostat is in a five-minute delay state. This setting keeps your equipment from harmful short cycling. This may take place 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 assistance.
    • 168—Wi-Fi radio error. Contact Lyric technical support at 800-633-3991. 170—Internal memory error. Reach 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 resumed. No action necessary.
    • 181/182—Install a new air filter. Clear the thermostat by touching “dismiss” after putting in a clean filter.
    • 184—Install a new humidifier pad. Clear the monitor by hitting “dismiss” after putting in a clean pad filter.
    • 185—Replace dehumidifier filter. Clear the screen by tapping “dismiss” after putting in a fresh filter.
    • 187—Rinse or put in a new ventilator filter. Clear the monitor by hitting “dismiss” after putting in a fresh filter.
    • 188/189—Install 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 complete 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 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 up. Get the Lyric app and follow the steps to configure your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005)

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

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

Our Experts are Ready to Provide Support

If you’re still experiencing issues after trying the troubleshooting steps, our professionals are available to help. Give us a call at 866-397-3787 and we’ll come to your house quickly to diagnose the problem.

If you have a dated thermostat, now is a great time to consider a new device. Thermostat technology has come a long way in recent years Ask us for more info on how smart thermostats can make your house more comfortable while helping save on energy bills all year.

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