How to Seal an RV Air Conditioner

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Things You'll Need

  • Socket wrench

  • Screwdriver

  • Rubber compression gasket

Most RVs have top-mounted AC units.

An air conditioner installed on an RV typically sits on top of the RV unit. When a new unit has been installed, it must be properly sealed to prevent leaks. You may also need to reseal an air conditioning unit if it has started to leak. The proper way to seal an RV air conditioner is to use a rubber compression gasket placed between the roof of the RV and the air conditioner.

Step 1

Disconnect the electrical connection or wiring harness for the air conditioning unit. If your RV has a circuit panel, turn off the circuit for the air conditioner as well.

Step 2

Remove the screws that secure the cover for the air conditioner, using a screwdriver.

Step 3

Remove the nuts, on the mounting bolts, that secure the air conditioner to the RV, using a socket wrench.

Step 4

Lift the air conditioning unit off the roof and set it on its side.

Step 5

Remove the old compression gasket from the bottom of the air conditioning unit.

Step 6

Set the new gasket into position on the bottom of the unit and then set the air conditioner back down on the roof of the RV.

Step 7

Tighten, by hand, the nuts on the mounting bolts and then secure them with the socket wrench.

Step 8

Tighten the screws used to secure the cover for the air conditioner.

Step 9

Reconnect the wiring harness and turn on the circuit, if necessary, to complete the project.


A minimum of ½ inch of gasket should be between the bottom of the air conditioning unit and the RV roof.

Obtain a rubber compression gasket by contacting the air conditioner manufacturer conditioner or by going to a RV dealer.


If the mounting bolts are not secure, the compression gasket will begin to leak.