I recently moved to a new house which uses the oil burner to heat hot water (previously I had a gas water heater). The hot water is too hot. I've been told that I can utilize the mixing valve to control the temperature of the water (I've been able to find the valve). I 've also been told that the hot water temperature should be around 120 degrees in order to save fuel. Just wondering if what I've been told is true and what is the best way to test the water temperature. Thanks.