How to Troubleshoot Honeywell Thermostat Errors

Honeywell is one of the best thermostat producers, and we proudly install them on a frequent basis in North America. They’re durable and dependable. Also, Honeywell is constantly advancing its technology, bringing more features for your residence.

Still, each thermostat can have errors every now and then. Due to this, we’ve put together this informative guide to walk you through troubleshooting.

While you can usually fix most thermostat problems on your own, they sometimes need Expert help. Our home comfort professionals are here to assist you when you need us. We’re just a call away at 866-397-3787.

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

What Model of Thermostat Do I Have?

There are three kinds 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 saving on utility bills.
  • Programmable—This thermostat includes a digital screen and arrows you touch to choose your desired temperature. You can also set daily programs to decrease the temperature when you’re gone and increase it when you return.
  • Smart—You won’t have to schedule any programs on this thermostat, as it learns your routine. It intuitively raises and lowers the temperature when you or other household members are away to help you save on utility costs. You can also adjust the temperature anywhere via your phone or other Wi-Fi-enabled device. 

As you know many technologically advanced products, there are common problems that may take place. Many of these issues don’t require pro support and are easy to fix on your own.

Common Honeywell Thermostat Troubles

Every thermostat has an exclusive group of codes matching the troubles that take place.

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

Here is a listing the most reported Honeywell thermostat problems. 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 take care of the trouble or you have a smart thermostat, there could be a wiring issue.

Next, you should check the power is flowing for your furnace or air handler. Make sure the switch close to the indoor unit is switched “up”.

Also, you should make sure all furnace cabinet or air handler doors/panels are tightly in place.

An unsecured panel may activate the safety switch, which disconnects power to the unit.

Infrequently, a blank screen can indicate you will need to buy a new thermostat.

HVAC Unit Won’t Work

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

In the summer, confirm you schedule the thermostat beneath the ambient temperature. When it’s cold, confirm it’s higher. This sounds silly, but we’ve seen it take place a lot of times.

Confirm the power switch close to your indoor unit is in the “on” position. You should also comfirm the cabinet doors or panels are tight on your furnace cabinet or air handler. An open panel can trigger the safety switch, diverting current to the system.

Equipment still won’t start? Verify circuit breakers haven’t flipped and that your HVAC system isn’t experiencing error codes.

“Cool On” or “Heat On” is Blinking

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

Then, check it’s telling the right system to run. This is usually shown by “cool on,” “heat on” or a picture.

If these words or the icon is blinking, your thermostat is in a five-minute delay state. This feature stops your unit from damaging short cycling. This may happen 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 866-397-3787 for assistance.
  • 168—Wi-Fi radio error. Reach Lyric technical support at 800-633-3991. 170—Internal memory error. Call Lyric technical support at 800-633-3991.
  • 171—Set date and time. Finish these settings so scheduling can run.
  • 173—Thermostat temperature sensor error. Reach Lyric technical support at 800-633-3991.
  • 175—AC power resumed. No action required.
  • 181/182—Replace air filter. Clear the display by hitting “dismiss” after putting in a clean filter.
  • 184—Install a new humidifier pad. Clear the display by tapping “dismiss” after installing a new pad filter.
  • 185—Put in a new dehumidifier filter. Clear the screen by tapping “dismiss” after installing a new filter.
  • 187—Rinse or install a new ventilator filter. Clear the screen by touching “dismiss” after putting in a fresh filter.
  • 188/189—Replace UV bulb. Call Service Experts Heating & Air Conditioning at 866-397-3787 for help.
  • 210—Register online for outdoor temperature. Download the Lyric app to do this step and ensure correct thermostat operation.
  • 388—Register online for remote access and exterior temperature. Use the Lyric app to finish 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 pick new Wi-Fi network.
  • 508—Wi-Fi not configured. Download the Lyric app and follow the steps 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 at 866-397-3787 for help.
  • 168—Wi-Fi radio error. Call Service Experts Heating & Air Conditioning at 866-397-3787 for help.
  • 170—Internal memory error. Reach Service Experts Heating & Air Conditioning at 866-397-3787 for support.
  • 171—Set date and time. Finish these settings so scheduling can operate.
  • 173—Thermostat temperature sensor error. Contact Service Experts Heating & Air Conditioning at 866-397-3787 for help.
  • 175—AC power reconnected. No action needed.
  • 177—Indoor temperature sensor error. Call Service Experts Heating & Air Conditioning at 866-397-3787 for assistance.
  • 178—Outdoor temperature sensor error. Call Service Experts Heating & Air Conditioning at 866-397-3787 for help.
  • 181/182—Install a new air filter. Clear the screen by touching “dismiss” after putting in a clean filter.
  • 183—Rinse humidifier tank and add a new water filter. Clear the monitor by hitting “dismiss” after doing these tasks.
  • 184—Replace humidifier pad. Clear the monitor by hitting “dismiss” after getting a new pad filter.
  • 185—Replace dehumidifier filter. Clear the monitor by tapping “dismiss” after adding a clean filter.
  • 186—Clean ventilator core. Clear the monitor by hitting “dismiss” after doing this task.
  • 187—Rinse or get a new ventilator filter. Clear the display by tapping “dismiss” after installing a new filter.
  • 188/189—Add a new UV bulb. Get in touch with Service Experts Heating & Air Conditioning at 866-397-3787 for support.
  • 210—Register online for outside temperature. Download the Lyric app to do this step and ensure correct thermostat operation.
  • 388—Register online for remote access and outdoor temperature. Use 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 choose new Wi-Fi network.
  • 508—Wi-Fi not set up. Download the Lyric app and follow the steps to connect your thermostat.

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

Our Experts are Ready to Provide Support

If you’re still having troubles after working through the troubleshooting process, our Experts are here to support you. Give us a call at 866-397-3787 and we’ll come to your house rapidly to determine the malfunction.

If you rely on an aging thermostat, now is a good time to consider a new thermostat. Thermostat technology has come a long way lately Ask us for more information on how smart thermostats can make your residence more convenient while helping save on utility bills all year.

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