My hot water is too hot, I have lowered the setting on the hot water thermostat to its lowest setting, but this has not made any difference. The Thermostat has also been changed. But this has not cured the problem. Sometimes the water is so hot that it comes out of the tap black. Any idea's

Did you change one or two thermostats? Did you change the upper thermostat; the 'brain' of a water heater?

XenoSapien