You don't need to be a mechanic. You just need to be a curator of airflow. Change the filter. Clear the drain. Keep the weeds off the outside unit. Write the dates down.
The most common emergency call isn't for a broken compressor—it’s for a dirty filter. A filter so clogged with dust, pet dander, and pollen that it suffocates the system, causing the evaporator coil to freeze into a solid block of ice in the middle of August. hvac maintenance checklist
Because the only thing worse than a checklist is the silence of a dead furnace on the coldest night of the year. And that silence is very, very loud. Print this list. Tape it to your furnace. And for the love of comfort, change that filter before the next heat wave hits. You don't need to be a mechanic