I assume you have lever handles. In that cse, you have to tighten the stem packings to create enough resistance so the weight of the handles does not turn the stems off.: REPLACED SHOWER STEMS WITH PRICE PFISTER #05034P . . BOTH FAUCETS. NOW HOT WATER SHUTS ITSELF OFF OR : REDUCES FLOW BY ITSELF UNLESS TURNED OFF WITH GREAT FORCE WHICH MAKES IT DIFFICULT TO ADJUST TEMPERATURE : WITHOUT BLOWING ONE OUT OF THE SHOWER. WHAT HAVE I DONE THATS WRONG OR ARE THE SEATS AT FAULT?