Honeywell Thermostat Won’t Turn On AC

“Is your home feeling more like a sauna than a sanctuary? If your air conditioning system isn’t turning on, troubleshooting might be time. Don’t let the sweltering summer temperatures get you down – let’s fix that Honeywell thermostat and get your AC back up and running!

This article will discuss methods to fix your thermostat so you can stay comfortable at your home.

Try Resetting the Thermostat to Factory Settings

1. Honeywell Lyric Y Family

You must press the reset button and wait for 5-10 seconds, later release the button.

2. Honeywell 4000/6000/8000

• Press and hold the “Reset” button for 5-10 seconds.
• Release the “Reset” button.

3. Honeywell 4000/7000/9000

• Press the “Menu” button.
• Scroll to “System Configuration” and press “Enter.”
• Scroll to “Restore Default Settings” and press “Enter.”
• Press “Enter” again to confirm the reset.

Restoring your thermostat to factory settings will reset it to its default settings and erase all of your custom settings. After the reset, you will need to enter any custom settings you have made on your thermostat.

Try Changing the Batteries 

The batteries in your Honeywell thermostat may be low or dead if the display is blank or the AC system won’t come on. The steps to changing the batteries in your Honeywell thermostat are as follows:

1. Find your thermostat’s battery compartment. Usually, the thermostat’s side or rear contains it.
2. Detach the outdated batteries. You should gently pry open the battery compartment of your thermostat with a coin or a screwdriver, depending on the model.
3. Install the new batteries. Make sure to use the correct type of batteries for your thermostat.
4. Close the battery compartment and make sure it is securely closed.
5. To check if the problem has been fixed, test the thermostat.

Notably, certain Honeywell thermostats are powered by low-voltage wire rather than batteries. If fresh batteries don’t make your thermostat work, it can be powered by low-voltage wire and require different troubleshooting. Getting in touch with a qualified HVAC specialist in this situation is essential.

Check Connections and Wiring for Any Damage

Checking the connections and wiring for damage is a smart idea if your Honeywell thermostat air conditioning system isn’t working. Here are the steps to follow:

1. Locate the AC system’s control panel. This is typically located outside the home, near the outdoor unit of the AC system.
2. Check the wiring connections at the control panel. Make sure that all of the wires are securely connected and that there is no visible damage to the wires.
3. Verify the wiring of the thermostat. Look for the wire connectors on the rear or side of the thermostat. Verify that the cables are properly connected and are free from any obvious damage.
4. Check the wiring between the control panel and the thermostat. From the thermostat to the control panel, follow the thermostat wires. Make sure the cables are safe and that there is no obvious damage.
5. It is preferable to call a qualified HVAC specialist to fix any damaged wiring or loose connections if you notice any.

Before checking the wiring, cut off the electricity to the AC system. The AC system’s fuse can be removed, or the circuit breaker can be turned off to do this.

Replace the Air Filter if it is Clogged

A clogged air filter can restrict airflow to the AC system, causing it to shut down. If your Honeywell thermostat is not turning on the AC system, it is a good idea to check the air filter and replace it if it is clogged. Here’s how:

1. Locate the air filter. This is typically located in the return air grill or the air handler of the HVAC system.
2. Remove the old air filter. Depending on your HVAC system, you may need to remove a panel or a door to access the filter.
3. Inspect the old air filter. If it is visibly dirty or clogged, it needs to be replaced.
4. Install the new air filter. Use the correct size and type of air filter for your HVAC system.
5. Close the panel or door and make sure it is securely closed.
6. Test the thermostat to see if the issue has been resolved.

Note: It is recommended to replace the air filter every 1-3 months to ensure optimal performance of your HVAC system.

Set Your Thermostat to Your Air Conditioning

It’s conceivable that the Honeywell thermostat is not set up properly to manage the AC system if it doesn’t turn on the air conditioning. The steps to configure your thermostat to your air conditioner are as follows:

1. Look over the thermostat’s settings. Ensure the temperature is lower than the ambient one and that the thermostat is set to “cool.”
2. Verify the wiring of the thermostat. Ensure that the thermostat is connected to the air conditioning system correctly.
3. Verify the settings on the control panel. Ensure the AC system is turned on and the control panel is set to “cool.”
4. Check the airflow. Ensure no obstruction is blocking the airflow to the AC system.
5. If you have tried all these steps and your AC system is still not turning on, it is best to contact a professional HVAC technician to diagnose and fix the problem.

Note: If you have made any changes to the thermostat or control panel settings, it is a good idea to test the AC system to ensure it is functioning correctly.

Set the Cooling Mode on Your Honeywell Thermostat

Follow these instructions to set your Honeywell thermostat to cooling mode:

1. The thermostat’s “System” button should be pressed. The system menu will appear as a result.
2. Scroll to “Cool” and press “Enter.”
3. Set the desired temperature. Use the up and down arrows to set the temperature you want the AC system to maintain.
4. Press “Enter” to save the settings.
5. Press the “Run” button to start the AC system.

Note: If your Honeywell thermostat is not turning on the AC system, it is possible that the thermostat is not correctly configured to control the AC system. In this case, it is a good idea to check the thermostat wiring and the control panel settings to ensure that the AC system is turned on and set to “cool.” If you have tried these steps and the AC system is still not turning on, it is best to contact a professional HVAC technician to diagnose and fix the problem.

Activate Your Furnace.

To switch on your furnace, do the following:

1. Look over the thermostat’s settings. Ensure the intended temperature exceeds the ambient temperature and that the thermostat is set to “heat.”
2. Check the furnace power switch. Make sure that the electric supply is turned on. This is typically located on the side or back of the furnace.
3. Check the furnace control panel. Ensure the control panel is set to “heat” and the furnace is turned on.
4. Check the furnace filters. Make sure that the furnace filters are clean and not clogged.
5. If you have tried all these steps and your furnace is still not turning on, it is best to contact a professional HVAC technician to diagnose and fix the problem.

Note: If you have made any changes to the thermostat or control panel settings, it is a good idea to test the furnace to ensure it is functioning properly.

Clean the Air Vents

Cleaning your air vents can increase the effectiveness and airflow of your home’s HVAC system. The steps to cleaning your air vents are as follows:

1. Cut off the HVAC system’s power. This can be accomplished by disabling the HVAC system’s circuit breaker or disconnecting its fuse.
2. Vent covers must be removed. You might need to use a screwdriver to remove the screws holding the vent covers, depending on the type of vent cover you have.
3. Vacuum the vents. Use a hose attachment vacuum to remove the vents’ dust and debris.
4. Clean the vent covers. Use a soft cloth and a mild cleaning solution to wipe down the vent covers.
5. Reinstall the vent covers. Make sure the covers are securely fastened in place.
6. Switch the power back to the HVAC system. 
7. Test the HVAC system to make sure it is functioning properly.

Note: It is a good idea to clean your air vents every few months to maintain good airflow and improve the efficiency of your HVAC system. Be sure to follow all safety precautions when cleaning your air vents, such as wearing protective gear and following the manufacturer’s instructions for your HVAC system.

Contact Honeywell Support if Nothing Else Works

If you have tried all of the troubleshooting steps and your Honeywell thermostat is still not turning on the AC system, it is a good idea to contact Honeywell support for further assistance. Here are some options for contacting Honeywell support:

1. Visit the Honeywell website and use the “Contact Us” form to send a message to Honeywell customer support.
2. Call the Honeywell customer support hotline. The phone number can be found on the Honeywell website or in the user manual for your thermostat.
3. Check the Honeywell website for troubleshooting tips and FAQs. You can find a solution to your problem using Honeywell’s online resources.
4. Consider hiring a professional HVAC technician. If you cannot resolve the issue with your Honeywell thermostat, it is best to contact a professional HVAC technician to diagnose and fix the problem.

Note: When contacting Honeywell support, be sure to have your thermostat model number and serial number handy and any other relevant information about the issue you are experiencing. This will help the support team better assist you.

Also Check : Best Honeywell Pro Series Thermostat

Conclusion

In conclusion, several possible problems could be the root of your Honeywell thermostat not turning on the AC system. Some possible solutions include resetting the thermostat to factory settings, checking the circuit breaker, replacing the air filter, checking the outdoor unit, checking the indoor unit, replacing the thermostat’s batteries, and checking the connections and wiring for any damage. 

If you have tried all these steps and the AC system is still not turning on, it is best to contact Honeywell support or a professional HVAC technician for further assistance.