Hot water heater off what happens when hot water turn on water?
if the water heater is off and you turn on a hot water faucet, cold water comes out.
You have nothing but cold water.
If you turned off the heat, but not the water line, you get unheated water. If you turned off the water, you get air.
the tank residual hot water comes out of the tap, until you get only cold water
18 gibbs 20
Assuming the valves to and from the water heater are open you'll get hot water until the tank empties then it will be cold.