How To Replace A Central Air Conditioner Drip Pan

If there are leaks around the outside unit of of your central conditioner or a bad smell coming out of the vents, check the drip pan. The drip pan catches water that drains from the coils. Sometimes, it rusts, or develops a crack, which means it needs to be replaced.

You should be able to replace the secondary drip pan yourself. Here are tips to replace a central air drip pan. 

Prepare to Work

For this project, you need:

  • work gloves
  • rag
  • screwdriver
  • wet vacuum
  • wrench
  • fine-grit sandpaper
  • water sealant
  • replacement pan

Shut off power to the unit from the breaker box, and set the thermostat on the lowest temperature. If you aren't sure which breaker controls the unit, turn off the breaker marked "MAIN." Post a note on the breaker box so no one accidentally turns the air on while you work.

Drip pans resemble a metal baking pan. A central air unit has two kinds of drip pans: primary and secondary.

The primary pan is commonly attached to the top of the evaporator coil, which is the only metallic coil in the unit. It may be welded or attached with other fasteners The secondary pan is installed below the primary pan, outside the coils.

Remove the Old Drip Pans

Use a screwdriver to detach the screws from the panel on the outside unit. Set the panel and screws aside.

Inspect the primary drip pan for clips or screws. Remove the clips or screws, and pull the pan out. If you don't find any fasteners, it cannot be replaced without removing the whole coil assembly.

Otherwise, detach the bolts on the drain line at the coupling with the wrench. The drain line is commonly attached between pans on the drain port. Repeat the process to remove the bottom drip pan.

Before you replace the pan, attempt to fix leaks. Sand the area, wiping sand dust with a rag. Apply the sealant, and let it dry. Reinsert the pan, turn on the power, and test for leaks.

Install the New Drip Pans

If the pan is full of water, don't touch the water in the pans, since it could be contaminated. Remove the water with a wet vacuum, then let the pans dry.

Slide the new pan on the coil, and tighten the connections. Reinstall the panel.

Restore power to the central air unit, and check for any issues. If you don't trust your skill, you can't remove the primary drip pan, or the unit doesn't work, contact an AC repair service.