I just purchased a home that is 100+ years old. The original bathtub and faucet are still installed and the faucet works fine. At some time in the past, someone installed a shower faucet and shower head. This works, but does not put out hot water. The water is not as cold as the cold side of the knob, but is barely lukewarm, if that. We, obviously cannot see how it was plumbed but the hot water line is obviously working going up to the area. Why would the tub faucet just 12" below get great hot water and the shower faucet not?? My friend took off the tab of the shower faucet handle to see if there is an adjustment and there is none. Any ideas?