Homeowners in Paradise Valley and Chandler are moving away from traditional storage-tank water heaters faster than most people realize, and the reasons are practical. Arizona’s hard water accelerates tank corrosion, energy costs keep climbing, and tankless systems now offer federal tax credits of up to $600 for qualifying units in 2025. This breakdown covers total installation costs ($1,800-$3,500 for most gas units), top brand comparisons including Rinnai, Navien, and Rheem, permit requirements under Arizona ROC rules, and the annual maintenance routine that protects your investment in a hard-water market. Whether you’re planning a full replacement or just exploring your options, the financial case for going tankless gets stronger the longer you plan to stay in your home.