I’ve had a dozen emails today asking about the possible dangers of turning your hot water tank off or switching it to vacation setting (concerns over breeding deadly bacteria).

Let me reassure you this is perfectly OK to do provided you give your water heater time to heat back up to full bacteria killing levels before showering.

You just need to put the water setting back to high heat when you return and do not use the showers for at least 4 hours (for a gas hot water tank) or at least 8 hours (for an electric hot water tank). The manufacturers recommend half that time but depending on the age of your tank and the amount of sediments in the bottom it could take longer to reach 140°F which is why I doubled the time just to be on the safe side.

If you have a tankless water heating system then it is not storing hot water so you don’t have to think about changing settings, it simply doesn’t run unless you turn on a tap so it stays off the whole time you are away.

You only get bacteria breeding if you store warm water (like in a hot water tank) of course you can also breed bacteria in a Jacuzzi tub or heated swimming pool but these are typically treated with chlorine or salt to kill bacteria making them safe to use.

If you have any other questions please do not hesitate to ask – we appreciate hearing from YOU!

Kay Francis

Francis Plumbing and Heating ClimateCare – We Care about you and your home!