One more note....it is ONLY in the showers. I have been told to turn up the hot water heater, but the dishwasher, washing machine, and sinks all get burning hot water. The showers are the only thing that don't, and it's only since those new knobs were put in the showers.
There is one knob, it turns left to turn it on, a little is cold, and all the way to the left is supposed to be hot.
And we can't call the guy who put it in to come back and fix it, it was someone from my hubby's old job and he has changed jobs and their relationship is not great now.