How Long Do Water Heaters Last in Arizona?
ENERGY STAR / U.S. Department of Energy guidance estimates these average lifespans:
| Type | Typical life |
|---|---|
| Storage tank | About 13 years |
| Tankless | About 20 years, with proper maintenance |
| Heat pump | About 10 years |
Why hard water matters
As water heats, minerals drop out as scale. In a tank, scale builds up as sediment on the bottom. In a tankless unit, it coats the heat exchanger. Phoenix's 2025 report itself says hard water "can cause some types of scaling in pipes and water heaters." With very hard water, maintenance matters even more.
Maintenance that helps
- Flush tank heaters to clear sediment. Follow the manufacturer's schedule, and do it more often with very hard water.
- Descale tankless units ([AFFILIATE LINK: Amazon-tankless-flush-kit]).
- Check the anode rod on tank heaters.
- Soften the water heading to the heater.
Signs it's time to replace
- Rusty hot water or rust at the fittings
- Water pooling under the tank
- Rumbling or popping noises (sediment)
- Running out of hot water sooner than it used to
- Age near or past the typical lifespan
Check the serial number to find your heater's age. Most brands encode the manufacture date in it.