Cleaning the condenser coil is a critical AC maintenance task. To clean the coil, turn the unit off and wait for the fan to completely stop. Then clear all debris and remove the top grille for easier access. Use a soft brush or vacuum to remove loose dirt, and follow with a commercial coil cleaner (or mix mild deterrent with water). Spray the cleaner and allow it to sit on the coil for a few minutes to loosen any remaining dirt. Then rinse the coil, gently, and allow the unit to dry.
Be sure to straighten any fins with a fin comb if they’re bent from the cleaning. Then reassemble your unit and turn the power back on. Experts recommend cleaning the condenser coil once a year.