I am reasonably well-versed in home plumbing, and my wife is having a problem with our bath/shower that is somewhat puzzling to me. After I have showered, she will take a bath, and more often than not when she runs water to heat/reheat the bath water, the shower head will somehow re-engage and begin to spray her. While she is using the hot water, the water from the shower head is cold, which I assume means that it was left in the pipe leading from the bathtub faucet to the shower head and has had time to cool since I was using it. Instant cold rain and angry wife! However, I have never heard of a shower head control, which is a common pull to use on the top of the faucet, engaging by itself. I also do not know why the head of the shower or the pipe leading to it would retain any significant water to cool off after I'm done when I turn the shower off 30 minutes earlier. Any thoughts?
