What are the risks if I run out of hot water?

If a large amount of hot water is used in a short period, the water heater won’t have enough time to reheat the incoming cold water.

When that happens, lukewarm water from the bottom of the tank can make its way to your taps. This creates a potential risk of exposure to Legionnaires’ disease, as lukewarm temperatures can encourage the growth of Legionella bacteria.