Turn off power to the air conditioner at the thermostat and breaker
Remove the access panel to reach the evaporator coils
Inspect the coils for dust, dirt, and mold
Vacuum loose debris with a soft brush attachment
Apply a no-rinse evaporator coil cleaner
Let the cleaner sit for the recommended time
Gently wipe accessible coil surfaces with a soft cloth or brush
Rinse only if the cleaner instructions require it
Clean the condensate drain pan and drain line
Reinstall the access panel
Restore power to the unit
Run the system and check for proper cooling and drainage
Schedule professional cleaning if the coils are heavily clogged or difficult to access