How to Troubleshoot Honeywell Thermostat Errors

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

Still, all thermostats can have problems every now and then. Due to this, we’ve prepared this useful guide to run through troubleshooting. While Honeywell thermostat troubleshooting problems are rare, they happen.

While you can typically solve most thermostat problems on your own, they often call for Expert support. Our home comfort professionals are available to support you when you need us. We’re just a call away at 866-397-3787.

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

What Model of Thermostat Do I Have?

There are three models of thermostats:

    • Manual—This is the classic dial-shaped thermostat. You won’t have error codes with this type, but it’s also the least efficient for lowering energy costs.
    • Programmable—This thermostat has a digital screen and arrows you touch to determine your desired temperature. You can also set daily programs to reduce the temperature when you’re gone and set it higher when you get back.
    • Smart—You won’t have to schedule any programs on this thermostat, because it adjusts to your day. It automatically raises and lowers the temperature when you or other household members are out and about to help you save on utility bills. You can also change the temperature anywhere via your phone or other Wi-Fi-enabled device.

As you know the majority of technologically advanced products, there are regular glitches that might occur. Most of these issues don’t need professional help and are uncomplicated enough to solve alone.

Common Honeywell Thermostat Troubleshooting Issues

Every Honeywell thermostat has a special kind of codes assigned to the glitches that take place.

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

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

Display is Blank

If the screen is blank on your programmable thermostat, you might 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 make sure the power is enabled for your furnace or air handler. Verify the switch near the indoor system is switched “on”.

Also, you should confirm all furnace cabinet or air handler doors/panels are securely fastened.

A panel that isn’t tight may activate the safety switch, which stops power to the unit.

Less frequently, a clear screen might signify you will need to get a new thermostat.

HVAC Equipment Won’t Work

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

During warm weather, confirm you put the thermostat beneath the ambient temperature. In the winter, make sure it’s higher. This sounds silly, but we’ve seen it occur many times.

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

System still won’t run? Confirm circuit breakers haven’t tripped and that your HVAC unit isn’t displaying error codes.

“Cool On” or “Heat On” is Blinking

First, make sure your thermostat is set to “cool” or “heat.”

Then, ensure it’s signaling the right unit to run. This is usually shown by “cool on,” “heat on” or an icon.

If this phrase or the illustration is flashing, your thermostat is in a five-minute delay status. This setting stops your unit from bad short cycling. This can happen 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. Contact Lyric technical support at 800-633-3991.
    • 171—Set date and time. Complete these settings so scheduling can take place.
    • 173—Thermostat temperature sensor error. Call Lyric technical support at 800-633-3991.
    • 175—AC power restarted. No action required.
    • 181/182—Replace air filter. Clear the thermostat by touching “dismiss” after putting in a new filter.
    • 184—Put in a new humidifier pad. Clear the monitor by hitting “dismiss” after adding a fresh pad filter.
    • 185—Put in a new dehumidifier filter. Clear the monitor by touching “dismiss” after adding a fresh filter.
    • 187—Clean or replace ventilator filter. Clear the display by touching “dismiss” after adding 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 outdoor temperature. Get the Lyric app to do this step and ensure accurate thermostat operation.
    • 388—Register online for remote access and outside 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 pick new Wi-Fi network.
    • 508—Wi-Fi not configured. Download the Lyric app and follow the steps to link your thermostat.

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

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

Our Experts are Available to Help

If you’re still experiencing troubles after going through the troubleshooting process, our Experts are here to help. Give us a call at 866-397-3787 and we’ll arrive quickly to determine the problem.

If you rely on an aging thermostat, right now is a good time to think over a new device. Thermostat technology has advanced over the last few years. Ask us for more details on how smart thermostats can make your house comfier while helping save on energy expenses all year.

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