Turn off power to the AC unit at the thermostat and breaker
Remove the access panel to reach the coil
Inspect the coil for dust, dirt, and debris
Vacuum loose dirt from the coil using a soft brush attachment
Spray the coil with a no-rinse AC coil cleaner
Let the cleaner sit for the time listed on the product label
Gently wipe accessible coil surfaces with a soft cloth or brush
Rinse the coil only if the cleaner instructions require it
Clean the drain pan and clear the condensate drain line
Reinstall the access panel
Restore power to the AC unit
Run the system and check for proper airflow and cooling
Schedule professional cleaning if the coil is heavily clogged or hard to reach