While repairs to an air-conditioning unit usually require a professional technician, periodic cleaning is something most homeowners can do. Cleaning the condenser and evaporator coils once each year can help keep your unit performing at its highest efficiency. While air-conditioning units vary depending on the model and manufacturer, basic cleaning procedures are similar.
Brush away any leaves and sticks around the exterior of your air-conditioning unit with your hands. Also pull out all weeds or grass growing against the sides of your unit.
Adjust your thermostat to the off position, and unplug your unit or use the disconnect switch to shut off the power to your unit.
Mix your coil cleaner with water, according to the instructions on the package, and fill your spray bottle with the mixed liquid.
Spray the coil cleaner solution onto the outside of the coils, squirting it through the protective screen. The cleanser should foam as it sets. Let the solution soak into the condenser compartment for 10 to 15 minutes.
Remove the fan guard cover from the top of your air-conditioning unit, and lift out loose leaves or trash that rests on the fan blades.
Take off the top of the condensing unit, leaving the fan attached, which will allow you to look and reach inside the interior compartment behind the condenser coils. Remove any visible debris from this compartment.
Place plastic bags over any visible electrical components and secure them with electrician’s tape to protect these components from moisture.
Apply a second coat of your coil cleaner solution over the outside surface of your coils. Allow this coat to set for an additional 10 minutes before removing.
Attach an adjustable spray nozzle to the end of your garden hose. Turn on your garden hose, and use the spray attachment to squirt a steady stream of water around the inside of your condenser unit to rinse the cleaner from the coils. The water will squirt through the housing to the outside, removing dirt and debris. Continue rinsing in this manner until the water runs clear.