How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the top thermostat producers, and we proudly install them on a regular basis in Fort Lauderdale. They’re sturdy and dependable. Plus, Honeywell is regularly updating its technology, resulting in more features for your household.

Still, each thermostat can experience troubles every so often. Due to this, we’ve prepared this helpful guide to walk you through troubleshooting. While Honeywell thermostat troubleshooting problems are rare, they do occur.

While you can often solve the majority of thermostat troubles alone, they sometimes need Expert support. Our home comfort professionals are available to support you when you need us. We’re merely a call away at 954-736-4314.

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

What Model of Thermostat Do I Have?

There are three types of thermostats:

Manual—This is the classic dial-shaped thermostat. You won’t run into error codes with this kind, but it’s also the least efficient for reducing utility expenses.
Programmable—This thermostat has a digital screen and arrows you press to set your desired temperature. You can also set daily programs to reduce the temperature when you’re at work and increase it when you get back.
Smart—You won’t have to schedule any programs on this thermostat, since it picks up on your routine. It instinctively changes the temperature when you or family members are away to help you save on heating and cooling bills. You can also adjust the temperature anywhere on your phone or other Wi-Fi-enabled device.

As you know many technologically advanced products, there are common malfunctions that might occur. The majority of of these troubles don’t require Expert help and are uncomplicated enough to fix alone.

Common Honeywell Thermostat Troubleshooting Problems

All Honeywell thermostats have an exclusive set of codes assigned to the malfunctions that occur.

Think how simple it can be to repair a computer by restarting it. In most situations, diagnosing a thermostat can be just as simple.

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

Display is Blank

If the screen is clear on your programmable thermostat, you might need to install new batteries. If that doesn’t fix the malfunction or you use a smart thermostat, there might be a wiring issue.

Next, you should check the power is on for your furnace or air handler. Confirm the switch near the indoor system is switched “on”.

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

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

Less frequently, an empty monitor can signify you will need to get a new thermostat.

HVAC Equipment Won’t Work

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

During warm weather, confirm you set the thermostat lower than the current temperature. When it’s cool, verify it’s higher. This sounds silly, but we’ve seen it happen a lot of times.

Confirm the power switch near your indoor unit is in the “on” position. You should also check the cabinet doors or panels are secure on your furnace cabinet or air handler. A loose panel can trigger the safety switch, cutting off electricity to the system.

Unit still won’t start? Verify circuit breakers haven’t turned off and that your HVAC unit isn’t displaying error codes.

“Cool On” or “Heat On” is Flashing

To begin, confirm your thermostat is set to “cool” or “heat.”

Then, ensure it’s signaling the correct system to start. This is typically shown by “cool on,” “heat on” or a picture.

If this phrase or the picture is pulsing, your thermostat is in a five-minute delay state. This feature protects your unit from harmful short cycling. This may occur 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 at 954-736-4314 for assistance.
168—Wi-Fi radio error. Call Lyric technical support at 800-633-3991. 170—Internal memory error. Contact Lyric technical support at 800-633-3991.
171—Set date and time. Finish 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 necessary.
181/182—Replace air filter. Clear the display by touching “dismiss” after adding a new filter.
184—Install a new humidifier pad. Clear the display by touching “dismiss” after installing a new pad filter.
185—Install a new dehumidifier filter. Clear the monitor by tapping “dismiss” after putting in a new filter.
187—Clean or install a new ventilator filter. Clear the thermostat by touching “dismiss” after putting in a clean filter.
188/189—Replace UV bulb. Call Service Experts Heating & Air Conditioning at 954-736-4314 for assistance.
210—Register online for exterior temperature. Use the Lyric app to complete this step and ensure proper thermostat operation.
388—Register online for remote access and outside temperature. Use the Lyric app to finish 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 choose new Wi-Fi network.
508—Wi-Fi not set. Use the Lyric app and follow the procedure to configure your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005)

164—Heat pump requires service. Call Service Experts Heating & Air Conditioning at 954-736-4314 for assistance.
168—Wi-Fi radio error. Call Service Experts Heating & Air Conditioning at 954-736-4314 for assistance.
170—Internal memory error. Contact Service Experts Heating & Air Conditioning at 954-736-4314 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 at 954-736-4314 for help.
175—AC power reconnected. No action needed.
177—Indoor temperature sensor error. Contact Service Experts Heating & Air Conditioning at 954-736-4314 for support.
178—Outdoor temperature sensor error. Reach Service Experts Heating & Air Conditioning at 954-736-4314 for support.
181/182—Replace air filter. Clear the thermostat by touching “dismiss” after putting in a new filter.
183—Clean humidifier tank and add a new water filter. Clear the monitor by tapping “dismiss” after doing these procedures.
184—Get a new humidifier pad. Clear the screen by tapping “dismiss” after getting a new pad filter.
185—Replace dehumidifier filter. Clear the screen by tapping “dismiss” after putting in a clean filter.
186—Rinse ventilator core. Clear the screen by hitting “dismiss” after completing this task.
187—Clean or install a new ventilator filter. Clear the screen by hitting “dismiss” after installing a new filter.
188/189—Add a new UV bulb. Contact Service Experts Heating & Air Conditioning at 954-736-4314 for help.
210—Register online for exterior temperature. Get the Lyric app to finish this step and ensure accurate thermostat operation.
388—Register online for remote access and outside 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 select new Wi-Fi network.
508—Wi-Fi not set up. Get the Lyric app and follow the process to connect your thermostat.

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

Our Experts are Ready to Provide Support

If you’re still running into problems after trying the troubleshooting steps, our pros are ready to help. Give us a call at 954-736-4314 and we’ll be out rapidly to determine the issue.

If you use a dated thermostat, now is a fantastic time to think over a new thermostat. Thermostat technology has gotten better over the last few years. Ask us for more information on how smart thermostats can make your house comfier while helping save on utility costs throughout the year.