electric water heater temperature and bacteria
Hi. I am about to install a new electric water heater to replace the one we have. I was talking to a plumber and he told me that electric water heaters need to be set to 140 degrees, and the outgoing water needs to be tempered with a mixing valve (add cold water to the outgoing hot water). He said the reason for the high temperature is kill bugs growing in the water. Legionaire's disease bacteria is suspected to grow in 120 degree electric water tanks.
Has anybody heard of this before? Is this for real? I was going to turn my temperature down low, but now I'm not sure. Also, if I do need a high temperature, can I keep it lower most of the time and just "pulse" it occasionally (couple hours per day), to cook the water?