CMP 1.5″ Threaded Pool and Spa Return Jet Winterizing Plug with O-Ring, 2 Pack, 25543-000-000

This is the 1-1/2 inch threaded winterizing plug with its o-ring, sold two to a pack. It seals a return jet or a filter drain so water cannot sit in the line over the off season.

Why plug the returns

Water left in a return line freezes and expands, and the fitting or the pipe is what gives way. Plugging the returns after the lines are blown out keeps water and debris out of them until the pool opens again. The o-ring on the plug is what holds the seal, so it is worth checking that it is seated and not nicked before the plug goes in.

Fit and second use

The plug is 1-1/2 inch male threaded, which is the standard size on most return jets and works with equipment from Hayward, Pentair, Jandy and Waterway. The same thread also replaces the Hayward SP1022C filter drain plug, so a spare from this pack has a job on the filter as well.

The material is specified to handle extreme cold without slipping or shrinking, which matters on a part that spends the whole winter under tension in a fitting.