Two climates, two kinds of water
Seattle, Tacoma, Everett and most Puget Sound cities draw soft water from Cascade watersheds. Tanks there rarely build heavy sediment, but anode rods wear faster, and damp basements corrode fittings. Spokane relies on the Spokane Valley-Rathdrum Prairie Aquifer, and the Tri-Cities draw on the Columbia River and groundwater; that water is harder, and eastern Washington winters are colder, so tanks work harder and need flushing more often.
Earthquakes and electrification
Water heaters across Washington must be seismically restrained so they cannot tip and break their gas or water connections. The state has also been moving toward electric heat pump water heaters through its energy code for new construction and through utility incentives, which makes heat pump units a common replacement choice in many homes.
Licensing, permits and costs
Plumbers in Washington are certified by the Department of Labor and Industries, and contractors must be registered with L&I. Cities issue permits for water heater replacement. Typical repairs run $150 to $650, and a standard gas tank replacement usually costs $1,700 to $3,800, higher in the Seattle area. See water heater replacement for details.
Choose your city below for local water, common problems and permit notes.