Indeed they do. Just ask our neighbors. They installed tankless, went on vacation, and the flexible hot water connecting hose to the hot water faucet failed in the upstairs bathroom. Hot water poured into the house...and happily stayed HOT and pouring in for a day or more before one of us neighbors noticed water pouring out from under the front door. The entire house heated up to about 120F and was a soggy mess. Almost a total loss. They lived in a rental for about 14 months while it was rebuilt.
Moral of the story. Check your flexible connections and replace as necessary. Better yet, install hard tubes and get rid of flex connections. And it is smart to install a leak detection system that will report to you on your smart phone that the house is leaking.
A leak detection system is still on my to-do list. ;>)
Better yet, cut everything off including the water when you go on vacay.
It is for this reason that we turn the water off when we go on vacation. I never want to return to a disaster if I can help it.
Turn off the water supply valve before going on vacation
damn... have to check into leak alarm as most of my house is pex
Or just turn it off if you’re leaving for an extended period