Quick answer
- Age 10+ years is the single biggest factor
- Water pooling at the base of the tank = replace, not repair
- Rusty hot water often means the tank is corroding from the inside
- Rumbling or popping is sediment — it lowers efficiency and capacity
When this applies
Repair vs. replace
A bad thermostat, heating element, or anode rod can be worth repairing on a newer unit. Once a tank is past ~10 years or leaking from the body, replacement is almost always the better value.
How it works
Why tanks wear out
A sacrificial anode rod corrodes so the steel tank doesn't. When the rod is used up, the tank rusts from the inside — and sediment from hard water builds on the bottom, insulating the burner and stressing the metal.
What to watch out for
A leak from the tank body
Water at the base (not a fitting) means the inner tank has corroded through. It can't be repaired and may fail suddenly — replace it before it floods.
Sediment buildup
Southern California's hard water accelerates sediment. It reduces hot-water capacity, raises bills, and causes the rumbling sound. Annual flushing helps, but a heavily scaled tank is on borrowed time.
Schedule service
Frequently asked questions
How long do water heaters last in Southern California?
Most tank water heaters last 8–12 years here; hard water tends to push them toward the shorter end. Tankless units can last longer with regular descaling.
Reviewed by John Stevenson Plumbing, Heating & Air. Based on manufacturer lifespan guidance and the water-heater replacements we perform in hard-water Southern California homes. Last updated 2026-06-18.