How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the top thermostat manufacturers, and we proudly install them on a usual basis in Kingston. They’re durable and dependable. In addition, Honeywell is frequently advancing its technology, offering more features for your residence.

Still, each thermostat can run into problems at one time or another. As a result, we’ve compiled this informative manual to walk you through troubleshooting.

While you can usually repair most thermostat issues on your own, they sometimes need Expert help. Our heating and cooling professionals are here to help when you need us. We’re merely a call away at 613-817-1591.

Let’s begin the process by determining what model of thermostat your home has.

What Type of Thermostat Do I Have?

There are three types of thermostats:

  • Manual—This is the classic dial-shaped thermostat. You won’t experience error codes with this one, but it’s also the least efficient for lowering utility bills.
  • Programmable—This thermostat features a digital screen and arrows you press to determine your desired temperature. You can also set daily programs to lower the temperature when you’re away and raise it 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 gone to help you save on heating and cooling bills. You can also change the temperature anywhere using your phone or other Wi-Fi-enabled device. 

As you know the majority of technologically advanced solutions, there are common malfunctions that may occur. The majority of of these troubles don’t require pro assistance and are uncomplicated enough to fix on your own.

Common Honeywell Thermostat Problems

All thermostats have an exclusive group of codes assigned to the problems that occur.

Think how easy it can be to fix a computer by restarting it. Many times, diagnosing a thermostat can be just as easy.

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

Display is Blank

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

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

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

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

Less frequently, a blank monitor might indicate you need to replace your thermostat.

HVAC Equipment Won’t Run

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

When it’s hot, confirm you schedule the thermostat beneath the room temperature. When it’s cool, make sure it’s higher. This sounds goofy, but we’ve seen it happen lots of times.

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

Equipment still won’t turn on? Verify circuit breakers haven’t tripped and that your HVAC equipment isn’t displaying error codes.

“Cool On” or “Heat On” is Blinking

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

Then, make sure it’s telling the correct equipment to start. This is typically indicated by “cool on,” “heat on” or an illustration.

If these words or the icon is pulsing, your thermostat is in a five-minute delay state. This mode stops your system from bad short cycling. This can occur if you lose power.

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 613-817-1591 for support.
  • 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. Complete these settings so scheduling can occur.
  • 173—Thermostat temperature sensor error. Call Lyric technical support at 800-633-3991.
  • 175—AC power restored. No action required.
  • 181/182—Put in a new air filter. Clear the display by tapping “dismiss” after installing a fresh filter.
  • 184—Replace humidifier pad. Clear the thermostat by touching “dismiss” after putting in a fresh pad filter.
  • 185—Install a new dehumidifier filter. Clear the thermostat by tapping “dismiss” after adding a fresh filter.
  • 187—Rinse or install a new ventilator filter. Clear the thermostat by hitting “dismiss” after putting in a clean filter.
  • 188/189—Get a new UV bulb. Call Service Experts Heating & Air Conditioning at 613-817-1591 for support.
  • 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 outdoor temperature. Use the Lyric app to do 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 choose new Wi-Fi network.
  • 508—Wi-Fi not set. Download the Lyric app and follow the steps to link your thermostat.

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

Honeywell T6 Pro Smart Programmable Thermostat (TH411OU2005) 

  • 164—Heat pump needs service. Contact Service Experts Heating & Air Conditioning at 613-817-1591 for assistance.
  • 168—Wi-Fi radio error. Call Service Experts Heating & Air Conditioning at 613-817-1591 for support.
  • 170—Internal memory error. Call Service Experts Heating & Air Conditioning at 613-817-1591 for support.
  • 171—Set date and time. Finish these settings so scheduling can work.
  • 173—Thermostat temperature sensor error. Reach Service Experts Heating & Air Conditioning at 613-817-1591 for assistance.
  • 175—AC power restored. No action needed.
  • 177—Indoor temperature sensor error. Contact Service Experts Heating & Air Conditioning at 613-817-1591 for help.
  • 178—Outdoor temperature sensor error. Contact Service Experts Heating & Air Conditioning at 613-817-1591 for assistance.
  • 181/182—Get a new air filter. Clear the thermostat by hitting “dismiss” after adding a fresh filter.
  • 183—Rinse humidifier tank and replace water filter. Clear the screen by touching “dismiss” after finishing these steps.
  • 184—Install a new humidifier pad. Clear the monitor by hitting “dismiss” after installing pad filter.
  • 185—Install a new dehumidifier filter. Clear the display by tapping “dismiss” after installing a fresh filter.
  • 186—Wash ventilator core. Clear the thermostat by touching “dismiss” after completing this task.
  • 187—Wash or get a new ventilator filter. Clear the screen by tapping “dismiss” after getting a new filter.
  • 188/189—Install a new UV bulb. Get in touch with Service Experts Heating & Air Conditioning at 613-817-1591 for assistance.
  • 210—Register online for outside temperature. Use the Lyric app to finish this step and ensure accurate thermostat operation.
  • 388—Register online for remote access and outdoor temperature. Download 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. Get the Lyric app and follow the process to connect your thermostat.

For more information, look at this thermostat’s user manual.

Our Experts are Available to Help

If you’re still experiencing issues after trying the troubleshooting list, our professionals are here to support you. Call us at 613-817-1591 and we’ll be out rapidly to figure out the malfunction.

If you use a dated thermostat, now is a great time to consider a new device. Thermostat technology has come a long way over the last few years. Ask us for more details on how smart thermostats can make your residence more convenient while helping save on utility bills all year.

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