Things You'll Need
New drain pan
Wear gloves when you remove the pans to avoid contact with water and sludge.
Drip pans, also called condensate pans, are placed under the air conditioner coils to catch any condensation that forms. There are two types of drain pans: a primary pan that is installed on the coil, and an auxiliary pan that is either installed inside the unit below the primary pan or under the unit. The primary pan usually cannot be easily replaced because it is welded to the coil. The interior auxiliary pans are the ones that are replaced most often because of ease of access. The pans located under the units are best left to certified professionals.
Replacing a Primary Drip Pan
Disconnect the power supply to the air conditioning unit.
Remove the hatch on the air conditioner that covers the coil unit.
Examine the drip pan to see if it is held in place by either clips or screws. If no fasteners are visible, it is an integral part of the coil and you will not be able to replace it.
Disconnect the drain line from the drip pan. Use a wrench or pliers to unscrew the drain line at the coupling with the drip pan.
Remove the clips or screws and slide the drip pan out. Do not touch the inside of the drip pan--any water in the pan could contain mold.
Insert the new drip pan, replace the clips or screws and reconnect the drain line.
Replace the hatch covering the coils and turn on the power to the unit.
Replacing an Interior Auxiliary Drip Pan
Shut off power to the unit.
Remove the hatch covering the coils.
Look inside at the bottom of the unit for the auxiliary pan.
Remove the drain line if one is present. Use pliers or a wrench to free the line from the coupling with the drip pan.
Lift the pan out of place and remove it from the unit. These pans are rarely fastened, but check to make sure.
Insert the new pan and reconnect the drain line.
Replace the hatch and turn on the power supply.
Vance Holloman is a residential contractor and freelance writer living in Atlanta. Much of his writing centers on the expertise he has gained from two decades in the construction industry. His work has appeared in newspapers, magazines and numerous online sites, including eHow.com and "Auburn Plainsman." Holloman has a Master's degree in business from the University of Maryland.