Most people find this page because their water heater is failing and they are bracing for the bill. So I will put the number up top instead of making you scroll for it.
In the Phoenix area in 2026, a standard tank water heater replacement usually runs somewhere between $1,200 and $3,800, installed. A tankless upgrade is a different animal and typically lands between $3,500 and $6,500 or more. Those are market ranges from public data, not a quote for your house. Yours could sit at either end depending on a handful of things I will walk through below.