I have hot water in every other faucet of my house, but the MBR Shower. While for 15 years it has given me hot water,it now only gets lukewarm water (not very good for taking a bath). I've replaced the shower mixing valve, but still do not get hot water. While it fixed a drip in the shower head, it did not fix the temperature issue. I tried multiple settings on the high temperature control on the shower valve and even removed the high temperature control stop, but it has not resulted in hot water in the shower. Could the water pressure balance valve be the culprit? Any other ideas?