Good point Mike. In many houses (mine for example) there is NO
way to separately regulate the domestic hot water temperature from
the heating system's temperature because the heater is a dual funtion
unit whereby the domestic hot water is a coil inside the heating system
hot water unit... and in today's hot water heating units (mine is only
three years old), the water temp setting cuts off at the high end at
around 180 degrees F.


My parents hot water heater is the same way. You do need to be
careful, but we should always be careful


We have that too, and every so often you get a cold shower because the
heating system
decided that the house was cold, and sucked all the heat out of the
unit. GRRRR!!!