How to Open a Lennox Furnace

Lennox residential furnaces are designed to help heat a whole home and range in energy efficiency from 80 percent up to over 98 percent, according to the Lennox website.

The units come with many different options, such as variable speed, dual fuel, insulated compartments, Energy Star rating and automatic ignition, among others. While the furnace can generally run without interference, it is occasionally necessary to open the furnace in order to perform maintenance or cleaning tasks. Opening the access panel on a Lennox furnace is straightforward. .

Turn off and disconnect power to the Lennox furnace.

Insert fingers into the tab on the front of the access panel.

Lift the panel up and off to remove.

Align the tabs on the panel with the slots on the furnace to replace the access door. Slide the tabs into place and push the access door closed. Be sure to close the access door firmly, as the furnace will not open if the door is ajar.


  • Stop immediately if the smell of gas is detected. Turn off the furnace and leave the house. Call your gas company or fire station for assistance.

About the Author

Meredith Jameson writes early childhood parenting and family health articles for various online publications. She holds a Bachelor of Arts in history from San Francisco State University.