Winter Pool Plugs for Returns, Skimmers & Plumbing

A three-dollar rubber plug is what stands between an empty return line and a cracked fitting in February. Winter pool plugs seal every opening in your circulation system once the lines are blown clear, so meltwater cannot creep back in and freeze inside your plumbing. PST Pool Supplies stocks the Anderson and Technical Products expansion plugs that professional closers actually use, covering pipe and fitting sizes from 1/2" all the way through 2½".

Choose the plug style by where it goes. Standard closed plugs — Anderson's 1-1/8", 1-5/8", 1-7/8", and 2" sizes — thread down and expand to seal a return eyeball or an empty line completely. Extended plugs from the Technical Products numbered series (#0, #2, #3, #6, #12 and more) reach past the fitting into the pipe itself, which matters on recessed returns and deep threaded fittings. Open plugs and duck-plug valves let trapped pressure escape rather than building behind a fully sealed line. Anderson has been making winterizing plugs in the USA for decades — see the full manufacturer range at Anderson Manufacturing.

Get the sizing right and installation is quick. Measure the pipe or fitting the plug seats into, not the eyeball you removed, and size to the pipe ID for extended plugs or the fitting for standard closed plugs. Blow the line clear first, then set the plug while air is still moving so it seats against a dry surface, and tighten the wing nut until the rubber visibly bulges — no wrench needed. For the skimmer opening you need a different tool entirely: an ice-compensating Gizzmo or skimmer cover. Pair plugs with a winterizing blower for a complete blowout, and see the full pool winterizing supplies range for everything else your closing needs. General closing best practices are outlined by the Pool & Hot Tub Alliance.

Stock a spare of every size you use — winter pool plugs are cheap, and finding out you are one short with a blower running and the light going is the worst way to end a closing day.