Will be away during freeze

quote:

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run hot water faucet to drain tank

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good luck with that draining the tank

I turned it off at the street on a vacant house when snowmageddon (a week of record deep freeze) was coming a couple years ago. Opened the faucets and flushed the toilets to empty the lines. Ignored the hard-to-access water heater in the attic and let it run. Came back a week later, and all was fine.

Later did the same for my house when I had to leave town before a deep freeze. Was able to access my water heater more easily, so I turned it way down. All was fine several days later.

Opening a hot water faucet won't drain the heater. As I understand it, the heater uses the pressure of incoming cold water to push the heated water out to the faucet. When the water is turned off, the heater just sits there full of hot water. Perhaps it could boil-out and go dry at some point and become an issue (not sure if it has a safety cutoff for that situation), but the one in the vacant house was good for a solid week without even turning down the heater.