Guest
i have seen this before it could be a couple of things.is your valve equipt with a balancing unit if it is this could be the culprit.if not turn the water off and remove the new cartridge check to see if there is any debris in it if so clean it out,before reinstalling the cartridge turn the water on SLOWLY to blow out any remaning debris.if none of this helps you may need to call a certified plumber.
