Hello all, I hope someone can help, I have a tub with a Symmons Temptrol dial to control the water hot/cold. It was working fine and for the last 3 weeks when I put the hot water on it will only last for about 1 1/2 min then it goes cold. I have checked the sink in the same bathroom and it works fine gets hot. I checked the sink and tub in the other bathroom and hot water come out of these as well. I was wondering if replacing the dial will help to correct this problem or if there was something else to check. Thanks.