Honeywell Thermostat Flashing “Cool On” [Complete Guide]

Honeywell Thermostat Flashing “Cool On”

Honeywell Thermostat Flashing “Cool On” Instructions are provided in a step-by-step format

One of two things could be causing your Honeywell Thermostat Flashing “Cool On”. Either your AC system is kicking in, which can take up to five minutes, or you may have a bigger problem that needs troubleshooting. The following steps should be followed.

Honeywell Thermostat Flashing Cool OnTime to upgrade?

A smart thermostat can save you money with its automatic home and away modes. No more wasting energy on unoccupied rooms!

Honeywell T9 Smart Thermostat

Smart rooms with voice control and sensors, DIY installation

Also read: Alexa Device Is Unresponsive

How does the “Cool On” indicator work?

I’d like to discuss Cool On a bit. This indicator is controlled by a thermostat. If the system is already working, it shows you Heat On. If the system is already working, it shows you Cool On. 

Your Honeywell thermostat flashing Cool On for only a moment is not indicative of a problem. You should not ignore these flashes. This prevents the compressor from being damaged and allows it to cycle for around five minutes before becoming damaged. It may also happen if there is a power outage.

How to troubleshoot a Honeywell Thermostat Flashing Cool On

Honeywell Thermostat Flashing Cool OnIf the “Cool On” indicator blinks continuously and the system does not receive cool air for at least five minutes, you need to troubleshoot the problem. Here are the steps to help you locate the issue.

1. Lower the thermostat to its lowest setting

Check here if the thermostat is unable to regulate the temperature. Adjust the controller’s settings to see if it needs cooling.

Temperatures should be set to a minimum. Assume that the fan mode is set to Auto and the mode is set to Cool. Check to see if it changes or if anything happens while it’s resting.

Also read: How to install Spectrum TV app on Samsung smart Tv

2. Make sure the thermostat is in setup mode or that the clock is set

Honeywell Thermostat Flashing Cool OnWhat recent power outages have you been experiencing? It is likely that your thermostat is in setup mode. It may blink during this process. Check that it is turned off or set. Adjust as needed.

3. Replace the thermostat batteries

Unless the thermostat batteries are fully charged, it will not be possible to cool or heat. If necessary, replace them.

There should be an indication of low battery power on the thermostat. You should see this after 2 months of using the thermostat.

Your thermostat might be using 24 VAC instead of batteries, in which case you should check your wiring. You will need to turn off the system in order to check the wiring. The C-wire can be found after removing the thermostat. Some thermostats may require unscrewing.

Also read: Where Is The Power Button on Vizio TV?

4. Check if Air Handler/Fans, Furnace, and AC unit have power

At this point, you may need some patience. When the initial diagnostic methods fail to produce improvements, it’s time to take action.

Check to make sure your units are not making any strange noises, such as humming or clicking.

Don’t risk anything. Are they powerful enough? Make sure power supplies and connectors are working properly. Make sure power supplies and connectors are connected properly.

Ensure that each component of the equipment is working properly. Make sure the doors are closed tightly. Are there any loose parts? Does anything block the equipment’s operation?

Circuit breakers should be in good working order. Also, try turning on and off equipment. It may be necessary to perform other technical actions, such as testing fuses with a voltmeter.

5. Check the indoor AC filter to see if it needs to be changed

You should have no problems with anything else in your house, including your air conditioner. If you need to replace your indoor filter, your home’s cooling will suffer greatly. As well as your thermostat and equipment, the quality of the air will also be impacted.

A new air conditioner filter should be replaced every three months. If your air filters are dirty or clogged, your air conditioner will work harder and break down more frequently. The temperature may drop drastically as a result of the component damage. Blocked registers can cause an indoor coil to partially or completely freeze.

Also read:

6. Check AC Coils and see if they are dirty

Your AC coils and indoor filter should be cleaned of dirt or debris. Your coil will become clogged with dirt after a period of time, preventing proper air flow. A lack of heat absorption or air cooling will result.

Clean the coils of your air conditioner if you notice buildup on its fins. Shut off the air conditioner before doing so.

Make sure the area around the AC is clean as well to prevent clogging sooner. Keep it away from nearby elements (such as plants or leaves) to ensure it has enough airflow.

7. Reset the thermostat

Honeywell Thermostat Flashing Cool OnYou can reset your thermostat to its factory default settings after separating possible problems from other equipment. You may forget some settings and programs if you leave them untouched, so be sure to write them down.

There are several ways to reset Honeywell thermostats, based on the model. If it’s powered by the C-wire, shut it off.

Your model will have a menu button that you can press (or hold) for a few seconds to find Reset, Factory, or Factory Reset. It might be under Preferences on other models. The link below contains instructions on how to reset your thermostat to its factory settings. Instructions may vary depending on the model.

Make any necessary changes after you’ve reset the thermostat.

Also read: Samsung 7 series vs 8 series

8. Check Manual

Don’t forget to bring your usual manual! You might find the answer there. Your thermostat’s manual may vary depending on its model. The display on the thermostat may be difficult for you to understand. Use your manual to figure out how to fix common problems.

Do you have a missing manual? You can probably find it online. Our handy list contains the manuals for most Honeywell thermostats. Our images make it easy to identify your model.

9. Hire a professional!

In the event that all of the above have failed, it might be time to talk to a professional. It may be a simple fix for an HVAC technician if your system has been working properly recently but suddenly stopped.

We can handle various issues, such as damaged wiring, faulty capacitors, blocked sensors, or blown fuses, with the help of trained technicians. There might be a need to further examine the compressor, condenser, or fan motor in your system.

When a new installation is being made, it is imperative to check the wires for matches. Your thermostat should be set up correctly as well. Your professionals can assist you with this.

Also read: Samsung TV Won’t Turn On No Red Light


Check out this guide to determine when Honeywell Thermostat Flashing “Cool On” is something to ignore, and when it is important to be concerned about.

If you follow the above steps, your computer should be recovered in some time and you will save some money. You can leave a comment regardless of whether this helped or if you have other troubleshooting tips.

Also read: 5 Steps To Create A Virtual Switch In SmartThings

Leave a Reply

Your email address will not be published. Required fields are marked *