My sis-in-law asked me to look at her shower valve as it trickles constantly no matter how the handle is turned on or off. It won't give any more water when it's turned on and keeps the same rate turned off so she had the main valve on the manifold turned off. I figured it was the valve cartridge so I got that out and took it to the hardware store and bought a new one, same model. But when I put it all back together it did exactly the same thing as the old cartridge did. It did not control the water rate at all and it constantly trickled out a steady stream of water. So I packed up the new cartridge and took it back for now (it was $45). What could be wrong with this valve? You'd think if it was the valve cartridge a new one would fix it. I did it exactly like several videos showed too. I'm kind of buffaloed as to how it can keep running like that.