Last Updated on February 26, 2023 by

Thermostats have become an essential part of life for those who want to keep their home’s temperature. As with many other household appliances, thermostats are prone to malfunction because of issues with software or hardware issue. Honeywell thermostat troubleshooting is also very essential.

Recently my Honeywell thermostat started acting strangely. The display was blank, along. It appeared that the HVAC unit wasn’t operating correctly. But, rather than opting to seek professional assistance, I decided to fix the system on my own. The problem is that thermostat malfunctions are pretty standard, and you can use various solutions to make the system work once more.

If your Honeywell Thermostat isn’t working, you can fix the issue by replacing the batteries or doing the hard reset.

How do you know what thermostat you have?

If you’re unsure which thermostat is used within your home, these tips can help you identify the model.


A manual thermostat can be shaped like a dial or feature a dial at its top like the one used on microwaves to control the timing. The manual thermostats aren’t widespread nowadays and may typically be located in older structures.


However, if your thermostat features an electronic screen, it does not have an app companion. The screen is also equipped with a handful of buttons that you can press to move through the menu.


Intelligent thermostats typically have large, vivid displays and a few buttons to adjust the setting. 

If what model you have for the Honeywell thermostat’s model is concerned, it’s recorded in the ID of your thermostat that is included with it. If you are in a hotel or lost the ID, you’ll be able to identify the model’s number by removing your thermostat off the wall. Most Honeywell thermostats are removed by lifting them off their wall plates. If the thermostat isn’t coming away, you can try sliding it or flipping it. 

Common Honeywell Thermostat Troubles

The process of troubleshooting a thermostat isn’t an easy job. The key is finding out the cause of the issue.

The display is Blank on Your Honeywell Thermostat

The display will usually turn blank for the following causes:

  • Batteries that are drained
  • Disrupted power
  • Open furnace door
  • Disconnected C-wire

To correct the problem, you must replace the batteries when you own a programmable thermostat. In contrast, if you own an old-fashioned or intelligent thermostat, ensure that the power supply isn’t damaged. Additionally, ensure that the power supply to your furnace and air handler is on (switch is turned on) and that the doors and panels for the air handler and the doors to the furnace cabinet are shut tightly.

HVAC Unit Won’t Work

Common HVAC problems include:

  • Airflows cool air when in high-temperature mode.
  • The system isn’t responding.

As absurd as it is before you start panicking, the HVAC unit may not be working. Additionally, when making the setting, be sure that it’s set more excellent or higher than the temperature in the room. Additionally, If the air handler panels or doors are closed, the doors to the furnace cabinet are not closed, and the HVAC system is not working correctly, it will not function properly. If the suggestions above aren’t working, try checking and setting your circuit breaker. When the system is up, wait five minutes before the compressor comes on.

“Cool On” or “Heat On” is Blinking

The “Cool On” and “Heat On indicators show the state of your system currently. If the thermostat is turned off, it won’t display any indicators. This built-in security feature is known as a ‘compressor protection timer.’

Why won’t my Honeywell thermostat work?

Try fresh batteries first if your Honeywell thermostat isn’t turning on. If it doesn’t work, check your circuit breaker and the thermostat for any loose wires. The Honeywell Thermostat may be hard reset to return to its factory default settings if all else fails.

How to troubleshoot a faulty Honeywell thermostat?

A few of the ways you can use to diagnose the issue with a malfunctioning Honeywell thermostat include:

Most of the time, switching the batteries will reset the system settings back to their initial state, thereby getting rid of any issues caused by bugs in the software.

  • Connect all wires that are connected with the thermostat.
  • Take the device off its wall mount.
  • Disconnect the batteries and then sit for 5 minutes.
  • Change the batteries, and connect the wires.
  • Switch on the system and then wait until you have five minutes.

There is a chance that the Honeywell Thermostat may continue to not function after changing your batteries.

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Fixing blinking “Cool On” Light

If the “Cool On light is generally flashing, this means the system is in the process of starting with the timer for safety is triggered to stop the compressor of the thermostat from failing. The safety feature is shut off after five minutes. If, however, it doesn’t turn off automatically, here’s how to fix it:

  • Check that the thermostat timer has been switched off and not in configuration mode.
  • Verify that the low battery indicator is lit.
  • Be sure that all furnace doors are shut.
  • Check that the AC filter isn’t blocked.
  • Verify that you can tell if the AC coils need cleaning.
  • Reset it with the previously mentioned method of changing the battery or by using an option to reset factory settings within the menu. 

Fixing blinking “Heat On” light

If the “Heat On” light blinks, it indicates the timer for safety was triggered to stop its compressor in the thermostat from failing. If it doesn’t turn off automatically, here’s how to fix it:

  • The temperature setting should be set to the lowest temperature that is available. Also, make sure that the fan is on auto.
  • Make sure the thermostat timer is switched off and not in setting mode.
  • Verify that the low battery indicator is lit.
  • Check that all furnace doors are shut.
  • Reset it following changing the battery or locate your factory reset choice on the menu. The latter option will only work with smart thermostats.


Honeywell thermostat troubleshooting is relatively simple to diagnose. If you’ve examined the wiring, batteries, and the furnace door and aren’t able to find a problem in the meantime, your thermostat has a hardware issue, or you’re in the wrong position to set your temperature too high and low enough. Use this permanently hold method to ensure that the system’s temperature and cooling settings are in order.

All you need to do is to hold the arrow ‘Up’ (for the heating) or the ‘Down’ arrow (for cooling) as well as the button that states ‘switch to permanent hold.’ Then, manually adjust the thermostat’s settings to a lower or higher temperature than outside. If none of the solutions discussed above work, you may want to seek help from a professional.


  • come with the ability to reset?

The Honeywell thermostat can be reset by changing batteries or using Factory Reset in the options.

  • How do I activate the Recovery Mode for your Honeywell thermostat?

The recovery mode indicates that the thermostat has been working towards getting a lower or more than the outside temperature.

  • How can I get around the recovery model of a Honeywell thermostat?

You can disable the recovery model of a Honeywell thermostat by adjusting the settings. You can also program or set the recovery mode following your preference.