My hot water heater has a SparcoMix AM mixing valve. There is a table that shows for water of various input temperatures what the output temperature of the water will be for each valve setting. My problem is that the turning valve itself has TWO numbers on it. How do I read it? Turning the valve counterclockwise will increase the output temp. I have it turned all the way counterclockwise and the output of my water heater is set at 130 deg F. According to the chart I have for that mixing valve the output should be 127 deg F but it is less than 120 deg F.
Another question. Why do I need a mixing valve for this application? I've always adjusted the water temp by the thermostat on the water heater itself.