Turn off power to the AC unit at the thermostat and breaker
Remove the access panel to reach the coils
Inspect the coils for dust, dirt, and debris
Use a soft brush or vacuum with a brush attachment to remove loose dirt
Spray the coils with a no-rinse AC coil cleaner
Let the cleaner sit for the recommended time
Wipe away loosened grime with a soft cloth if needed
Rinse the coils gently if the cleaner requires it
Clean the surrounding drain pan and drain line
Reinstall the access panel
Restore power to the unit
Replace or clean the air filter regularly to help keep coils clean