How to Troubleshoot Honeywell Thermostat Errors

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

However, each thermostat can have errors from time to time. Due to this, we’ve prepared this valuable manual to run through troubleshooting. While Honeywell thermostat troubleshooting problems are rare, they happen.

While you can often fix most thermostat troubles alone, they often call for Expert assistance. Our HVAC pros are available to assist you when you need us. We’re only a call away at 866-397-3787.

Let’s get started with the process by determining what model of thermostat your house has.

What Model of Thermostat Do I Have?

There are three models of thermostats:

    • Manual—This is the typical dial-shaped thermostat. You won’t have error codes with this type, but it’s also the least efficient for lowering energy expenses.
    • Programmable—This thermostat features a digital screen and arrows you use to choose your desired temperature. You can also set daily programs to decrease the temperature when you’re gone and set it higher when you get back.
    • Smart—You won’t have to set any programs on this thermostat, since it learns your routine. It instinctively adjusts the temperature when you or other household members are out and about to help you save on energy costs. You can also adjust the temperature anywhere on your phone or other Wi-Fi-enabled device.

As you know most technologically advanced solutions, there are several glitches that might happen. Many of these issues don’t require pro help and are uncomplicated enough to repair on your own.

Common Honeywell Thermostat Troubleshooting Issues

Every Honeywell thermostat has a unique set of codes that correspond to the problems that take place.

Think how simple it can be to restore a computer by restarting it. In most cases, troubleshooting a thermostat can be just as easy.

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

Display is Blank

If the screen is blank on your programmable thermostat, you may need to put in new batteries. If that doesn’t fix the issue or you have a smart thermostat, there could be a wiring malfunction.

Next, you should make sure the power is on for your furnace or air handler. Confirm the switch by the indoor equipment is in the “on” position.

Additionally, you should make sure all furnace cabinet or air handler doors/panels are sturdily fastened.

An unsecured panel may trigger the safety switch, which cuts off power to the equipment.

Infrequently, a blank screen may signify you need to replace your thermostat.

Comfort System Won’t Work

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

In the summer, make sure you put the thermostat below the room temperature. When it’s cool, verify it’s higher. This sounds absurd, but we’ve seen it take place many times.

Ensure the power switch close to your indoor system is in the “on” position. You should also make sure the cabinet doors or panels are closed on your furnace cabinet or air handler. An open panel can trigger the safety switch, cutting off electricity to the system.

Equipment still won’t run? Verify circuit breakers haven’t turned off and that your HVAC equipment isn’t showing error codes.

“Cool On” or “Heat On” is Flashing

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

Then, check it’s telling the appropriate equipment to turn on. This is often demonstrated by “cool on,” “heat on” or an illustration.

If this set of words or the illustration is blinking, your thermostat is in a five-minute delay status. This feature keeps your system from damaging 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 must be serviced. Call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for support.
    • 168—Wi-Fi radio error. Reach Lyric technical support at 800-633-3991. 170—Internal memory error. Contact Lyric technical support at 800-633-3991.
    • 171—Set date and time. Complete 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 required.
    • 181/182—Put in a new air filter. Clear the monitor by hitting “dismiss” after installing a fresh filter.
    • 184—Install a new humidifier pad. Clear the screen by hitting “dismiss” after installing a new pad filter.
    • 185—Put in a new dehumidifier filter. Clear the screen by touching “dismiss” after adding a clean filter.
    • 187—Rinse or replace ventilator filter. Clear the thermostat by tapping “dismiss” after adding a fresh filter.
    • 188/189—Install a new UV bulb. Call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for help.
    • 210—Register online for outdoor temperature. Use the Lyric app to complete 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 correct thermostat operation.
    • 399—No Internet. Check 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. Download the Lyric app and follow the process to configure your thermostat.

For more information, 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. 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. Finalize these settings so scheduling can run.
    • 173—Thermostat temperature sensor error. Call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for assistance.
    • 175—AC power restored. No action necessary.
    • 177—Indoor temperature sensor error. Call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for help.
    • 178—Outdoor temperature sensor error. Call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for support.
    • 181/182—Get a new air filter. Clear the monitor by touching “dismiss” after adding a clean filter.
    • 183—Rinse humidifier tank and replace water filter. Clear the display by hitting “dismiss” after doing these tasks.
    • 184—Replace humidifier pad. Clear the monitor by tapping “dismiss” after adding a new pad filter.
    • 185—Install a new dehumidifier filter. Clear the monitor by tapping “dismiss” after putting in a clean filter.
    • 186—Rinse ventilator core. Clear the display by tapping “dismiss” after doing this task.
    • 187—Wash or install a new ventilator filter. Clear the display by hitting “dismiss” after installing a new filter.
    • 188/189—Replace UV bulb. Reach Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for help.
    • 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 outdoor temperature. Download the Lyric app to finish 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 connected. Get the Lyric app and follow the process to connect your thermostat.

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

Our Experts are Ready to Provide Assistance

If you’re still experiencing problems after going through the troubleshooting list, our Experts are available to help. Reach us at 866-397-3787 and we’ll be out rapidly to diagnose the malfunction.

If you have an aging thermostat, now is a great time to think over a new device. Thermostat technology has advanced in recent years Ask us for more information on how smart thermostats can make your home more comfortable while helping save on energy costs all year.

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