Went out to clean my C1200 cartridge filter this morning and can't open it. I can turn the knob about 8 turns before I get a loud click/thump and no more progress. I can tell something is stripped. I tried tightening it up and loosening it but at the same point I got the same result. I also tried putting upward and downward pressure on the top but it didn't help.
My question is how best to get this thing opened up to inspect what the problem is. I was able to screw it back down tight so it is operating OK, but I need to get this figured out quick.
I'm going to be on the road for a couple of days so I won't be able to try anything until Sunday night, but it just happened so I decided to ask now.