if your house isnt that big, then you can find the gas switch. should have a red plate board behind it and say GAS. if ur heater is on and you switch it to the off position, you will hear the heater go off. all water heaters are gas tho i think.
you can look at the heater to see if it has a plug or a gas line or both!
Got it thank you so much I needed it for a physics project(:
no problamo =)