My goal as a water heater advisor is to save you money. How does your water heater relate to your wallet? Most likely, one utility will be less expensive to operate than the other. My guess is most households do not have a preference. The area in which you live might dictate the type of water heater you will install. Certain areas of the country are predominately gas, while others are mainly electric. If you have a choice, hopefully this info will help you decide. You can save from the start by choosing the correct heater for your household.
Assuming you have a choice, how do you choose? Ask yourself if the present heater does a sufficient job. Does it supply enough hot water for your family? If you're replacing an existing water heater, check to see what type you have now. Is it gas, electric or even propane? If your heater has done a good job for your family, why not stay with the same type? Usually that will be an easier and less expensive installation.