My Moen posi-temp cartridge was faulty so I replaced it. When I reassembled it, I could not get the clip back in, so I went back to the store and got it replaced. I still had the same problem. The original was 10 years old, so I figured it had changed slightly so I dremeled a small groove in each side to allow the clip to go in.
When I reassembled everything it worked perfectly for all of my testing. First real shower, everything was fine for several minutes (enough time to get my hair really soapy... ) Then there was a bang, and I lost all water pressure, just a dribble left..
I checked everything and it seemed fine, the rest of the taps are OK, and the hand-held shower works, it just seems like the back-pressure from the drencher is the problem. I cleaned the shower head and checked the valve between the showers, but that's all fine... any ideas please?