I've got an off-line Hayward chlorine tablet feeder on my pool (it has a 1/4" hose that taps off some water from the pressure side of the pump before the filter, and it outputs via 1/4" line to the return lines after the filter).
This thing has a screw-top to seal the chamber where the chlorine tablets go, and it has a latch mechanism - if you screw it on far enough, it latches to prevent the top vibrating off.
This thing is only 3 or 4 years old.
At this point I can't close it completely (it's simply too tight to screw on any further). When last I did have it completely closed, it took me over an hour to get it apart. It doesn't leak, and various tests (unscrewing various fittings) shows that it is working.
Anyone know what's gone wrong here? It's almost like the plastic has changed shape in some way. Any idea how to fix it? It's not an expensive part ($60 or so), but it's only a few years old, and it seems to me it shouldn't need replacing already.