As you may know both P42 reefers drain into the aft shower sump. In the past Ive inserted drain plugs inside each reefer to help reduce cold air exiting through the drain. No big deal for the freezer plug but you have to empty the refrigerator and lift out the plastic panel to get to the plug. I now insert the plug into the sump end of the drain making it much easier to occasionally release any water that has accumulated, but at the same time keep cool air in.

Terry