Re: Help with multiport valve and spider gasket
I believe some multi ports are more prove to premature failure than others.
I have a very old valve which uses a gasket design with extremely narrow separating "bars". If I accidentally operate the valve incorrectly, the gasket will pop out of position, never to work again. One mistake and that's it! The rubber swells ever so slightly over time so once the gasket has popped out, it cannot be made to set back in place, pooching up in the center of the bars slightly and rolling out of position the next time the valve is rotated.
That's why I think that for some multi-ports, it's important to follow the manufacturer's recommendation to glue the gasket in place. This allows it to survive occasional "operator errors", and the natural effects of slight swelling. The glue will help keep the gasket in position, although cleaning out the old glue certainly makes it more difficult for subsequent replacements.
There's several threads in this forum where the subject of "to glue or not to glue" has been discussed with valid pros and cons from both viewpoints. I've never actually glued my gasket in place, suffering through many annual replacements without glue, but I have a new gasket in hand and I'm pretty sure following the manufacturer's recommendation will extend it's longevity.
You may want to ask your installers what they did.