Remove Rust From Your Air Conditioning Condenser

Patrick Lee

Keep your outdoor condenser in good shape by keeping it maintained. If you notice rust forming on the condenser, remove it so that the mechanical parts inside are able to move the proper way. After finishing, you can add a couple coats of paint to give the condenser a fresh appearance.


  • screwdriver
  • masking tape
  • nylon brush
  • fine grit sandpaper
  • hand sander
  • all purpose cleaner
  • clean cloth
  • plastic sheeting
  • scissors
  • automotive spray paint
  • tarp
  • vacuum cleaner

Inspect And Sand The Rusted Surfaces

Turn off the air conditioning unit before beginning. Begin inspecting the condenser cover, locating rusted areas. Open the cover with a screwdriver and inspect the interior sections. Pay close attention to the fins and fan assembly. Sometimes, moisture gets into condenser units, causing rust to form. Remove loose paint chips by running a nylon brush over the rusted areas. Finish up by sanding these sections with fine grit paper. If you find that the rust isn't coming off quickly, switch to a lower grit paper.

Clean The Condenser And Protect Areas Before Painting

Use all purpose cleaner and a cloth to clean dirty surfaces. Any debris that is inside of the condenser can be removed by hand. If a large mess is present, use a vacuum cleaner to remove it. Rusted areas can be repainted with automotive paint. This type of paint will last for a long length of time and won't fade or chip when exposed to moisture. Cover areas that you do not want exposed to the paint.

Cut out pieces of plastic sheeting and secure them with masking tape. Any hardware and materials that haven't been previously painted should be covered. Lay a drop cloth on the ground around the condenser before you begin. Spray even coats of paint from a couple feet away. Allow several minutes to pass before applying a second coat. After a couple hours, remove the masking tape. Allow the paint to dry overnight before using your air conditioner. 

Keep The Condenser Clean

The paint will last longer if you keep the heating and air conditioning condenser clean. Inspect the conditions of the cover and the contents inside throughout the year. Remove branches, leaves, dirt, and other debris. By keeping your unit clean and dry, rust will not be likely to form and you will maximize the amount of time that the paint lasts. This will save you time and money in the long run.