I have a Haward c1200 filter which I had someone install for me a couple of years ago. It's worked fine until just the last week or so. All of the sudden one day water came blasting out between the base and lid of the filter casing. I noticed there was about a 1/4 inch gap between the base and the lid and figured it hadn't been put on tightly the last time it was cleaned. I opened it up, made sure the cartridge was in straight, and made sure the lid was on straight and tight. But there is still about a 1/4 inch gap. It's close enough that I can run the pump for a while, but eventually when the pressure gets high enough, the part of the o-ring gets forced through the gap and water blasts out enough.
I tried a second filter cartridge and the gap is about the same. Seems like it should be a fairly simple issue to fix, but I can't figure out how to get the lid down further to eliminate the gap. Any ideas?