thank you for your help... That does makes sense. It only leaks when the water faucet is turned on. Now when you say inspect the valve core inside the wall, that does not require any removal of the tub enclosure right? I should still have access to some parts of the faucet other than the knobs right? I will relay this to my husband so he can look at it. When we originally replaced the faucets we only put on new faucet knobs, so the rest is old, that could be a factor as well? Thanks!!!