Originally Posted by nealtw
150 at the tank is needed to keep bacteria from growing in the tank.
I don't often get to discuss risk with the guys at the gym so please indulge me.
According to Ropeik and Gray, "Risk is the probability that exposure to a hazard will lead to a negative consequence."
The risk of being burned is pretty clear once exposed to hot water, as shown above. On the other hand, once burned-twice shy.
With bacteria in the WH the risk is not that all that clear and the exposure to the hazard and how hazardous it is (how many die per 100,000 people per year or during their lifetime from hot water heater bacteria?) is also kind of murky.
I guess I'd leave my heater at the min temp recommended for my dishwasher, 120F.
But I may be biased because I spilled hot water for my coffee on my hand and got second degree burns and had to usehttp://en.wikipedia.org/wiki/Silver_sulfadiazine
and the skin color of that hand is still not normal.