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 sturdy and trustworthy. Plus, Honeywell is constantly advancing its technology, bringing more features for your household.

Still, all thermostats can have errors every so often. Due to this, we’ve put together this useful manual to go over troubleshooting. While Honeywell thermostat troubleshooting problems are rare, they happen.

While you can usually fix many thermostat problems alone, they often need Expert support. Our HVAC professionals are available to assist you when you need us. We’re merely a call away at 866-397-3787.

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

What Type of Thermostat Do I Have?

There are three kinds of thermostats:

    • Manual—This is the older dial-shaped thermostat. You won’t experience error codes with this one, but it’s also the least efficient for saving on energy bills.
    • Programmable—This thermostat has a digital screen and arrows you press to set your desired temperature. You can also use daily programs to decrease the temperature when you’re gone and set it higher when you come home.
    • Smart—You won’t have to set any programs on this thermostat, as it picks up on your day. It intuitively adjusts the temperature when you or family members are away to help you save on heating and cooling costs. You can also adjust the temperature anywhere using your phone or other Wi-Fi-enabled device.

As you’re aware most technologically advanced products, there are common problems that can happen. The majority of of these troubles don’t need Expert assistance and are simple to fix alone.

Common Honeywell Thermostat Troubleshooting Issues

All Honeywell thermostats have a unique set of codes that correspond to the issues that happen.

Think how uncomplicated it can be to repair a computer by restarting it. For the most part, troubleshooting a thermostat can be just as simple.

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

Display is Blank

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

Next, you should check the power is enabled for your furnace or air handler. Confirm the switch close to the indoor system is in the “on” position.

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

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

Infrequently, a clear monitor may mean you need to replace your thermostat.

HVAC Unit Won’t Run

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

In the summer, confirm you put the thermostat below the current temperature. When it’s cool, make sure it’s higher. This sounds absurd, but we’ve seen it happen a lot of times.

Make sure the power switch close to your indoor equipment is in the “on” position. You should also check the cabinet doors or panels are closed on your furnace cabinet or air handler. A loose panel can activate the safety switch, cutting off power to the equipment.

System still won’t turn on? Verify circuit breakers haven’t turned off and that your HVAC unit isn’t experiencing error codes.

“Cool On” or “Heat On” is Blinking

To start, verify your thermostat is on “cool” or “heat.”

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

If this set of words or the illustration is pulsing, your thermostat is in a five-minute delay status. This setting protects your equipment from damaging short cycling. This could take place if you lose power.

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 support.
    • 168—Wi-Fi radio error. Contact Lyric technical support at 800-633-3991. 170—Internal memory error. Contact Lyric technical support at 800-633-3991.
    • 171—Set date and time. Finalize these settings so scheduling can run.
    • 173—Thermostat temperature sensor error. Contact Lyric technical support at 800-633-3991.
    • 175—AC power resumed. No action needed.
    • 181/182—Replace air filter. Clear the display by touching “dismiss” after adding a clean filter.
    • 184—Replace humidifier pad. Clear the monitor by hitting “dismiss” after putting in a new pad filter.
    • 185—Put in a new dehumidifier filter. Clear the display by touching “dismiss” after putting in a fresh filter.
    • 187—Clean or replace ventilator filter. Clear the screen by hitting “dismiss” after installing a fresh filter.
    • 188/189—Get a new UV bulb. Contact Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for help.
    • 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. Get the Lyric app to finish 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 select new Wi-Fi network.
    • 508—Wi-Fi not configured. Use the Lyric app and follow the process to link your thermostat.

For more details, see 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 assistance.
    • 168—Wi-Fi radio error. Call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for assistance.
    • 170—Internal memory error. Call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for help.
    • 171—Set date and time. Finalize these settings so scheduling can operate.
    • 173—Thermostat temperature sensor error. Call Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for support.
    • 175—AC power resumed. No action necessary.
    • 177—Indoor temperature sensor error. Contact Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for support.
    • 178—Outdoor temperature sensor error. Reach Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for help.
    • 181/182—Install a new air filter. Clear the display by hitting “dismiss” after adding a new filter.
    • 183—Wash humidifier tank and add a new water filter. Clear the screen by tapping “dismiss” after doing these steps.
    • 184—Install a new humidifier pad. Clear the thermostat by touching “dismiss” after adding a new pad filter.
    • 185—Install a new dehumidifier filter. Clear the screen by tapping “dismiss” after adding a fresh filter.
    • 186—Clean ventilator core. Clear the thermostat by hitting “dismiss” after completing this task.
    • 187—Wash or get a new ventilator filter. Clear the monitor by tapping “dismiss” after getting a new filter.
    • 188/189—Add a new UV bulb. Reach Service Experts Heating, Air Conditioning & Plumbing at 866-397-3787 for assistance.
    • 210—Register online for outdoor temperature. Use the Lyric app to do this step and ensure proper thermostat operation.
    • 388—Register online for remote access and exterior temperature. Get the Lyric app to finish 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 up. Get the Lyric app and follow the procedures to connect your thermostat.

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

Our Experts are Available to Provide Assistance

If you’re still running into problems after working through the troubleshooting steps, our Experts are here to help. Give us a call at 866-397-3787 and we’ll be out as fast as we can to determine the malfunction.

If you use an aging thermostat, right now is a fantastic time to think about a new device. Thermostat technology has gotten better in recent years Ask us for more info on how smart thermostats can make your residence more convenient while helping save on utility costs all year.

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