||You have written previously that you can turn on the hot water in a building on Shabbat because it is like a refridgerator. My building, however doesn't have a hot water tank. Instead, when you turn on the hot water, a flame is turned on which heats water as it goes through the pipes. As far as I can tell, the mechanism is nonelectric.
1) Can I turn on the hot water on Shabbat?
2) Yom Tov?