do you need your gas on.. for it to produce hot showers

Why would you need gas to heat water? That's unsafe, and most homes now are all-electric. I replaced our old gas water heater with an electric that doesn't see much use, as the sun heats our water before it even enters the house, and it doesn't freeze here, so the water is always tolerably warm, above 50 degrees F in the winter. If you have a gas water heater and are in cold country, obviously you would need the gas on to heat the water if you want it hot, or replace with a solar water heater or electric. (Arizona.)

This model does not heat water.