abercanadian wrote:Looking from the rear, it would be at about 7 o'clock. There should be a plastic piece sticking up, about an inch and a half long and about 1/4" thick, inserted into the drain. This piece has slits in it that allow water to pass through and down the pipe. It does get clogged, good to keep an eye on it in winter. If you have no plastic piece ...get one!
I suspect the drain filter is long gone.
Clean out all the muck with a none sharp object. You will find the drain hole