Gas water heaters rely on natural gas or propane to heat the water. The installation cost for a gas water heater can range from $500 to $2,500. If you have any concerns concerning wherever and how to use gapnet-technologies.com, you can contact us at our site. Installation costs depend on the tank size and any additional work needed. But remember that while gas models are less expensive to operate, you do need an existing natural gas line to be able to use them.