.can gas hot water tank freeze

It can freeze, under certain conditions. It has to be off, and the surronding area has to be below freezing. If the temperature is above, then it is very unlikely, I suppose it is possible for the gas to freeze it, but it would go through a lot of gas, and you would smell it quite a bit.

Hi Moradi...

Very unlikely that the water heater itself has frozen... ;)

In fact, what is more likely is that the water heater has lost its pilot (if gas heater) or a thermostat has shut the electric flow to the heating elements (if an electric water heater).

What kind of water heater do you have... gas or electric?

MARK