Most water heaters don't fail without warning — they fail after months of warnings nobody recognized. Here's how long each type lasts, what shortens its life, and the seven signs we tell our own customers to watch for.
Lifespan
How long they last
Tank water heaters
8–12 years
In Southern California's hard water. Annual flushing and anode rod replacement push toward the high end; neglected tanks die young.
Tankless water heaters
15–20+ years
With annual descaling. Skip maintenance in hard-water areas and scale will kill the heat exchanger years early.
Warning Signs
7 signs your water heater is failing
1. It's over 10 years old
Check the serial number or the rating plate for the manufacture date. Past 10 years, you're on borrowed time — start planning, even if it's working fine today.
2. Rumbling, popping, or banging
Sediment hardened on the tank bottom makes the burner overheat trapped water. A flush may help early on; persistent noise on an old unit means the end is near.
3. Rusty or discolored hot water
Rust-colored hot water (but clear cold water) usually means the inside of the tank is corroding. Once the tank itself rusts through, it leaks — and tanks can't be patched.
4. Water pooling at the base
A leak from the tank body means internal failure — replacement, not repair. (Leaks from fittings or valves above the tank are often fixable; we'll confirm the source.)
5. Hot water runs out faster than it used to
Sediment displaces water capacity and insulates the burner, so recovery slows and usable hot water shrinks. It's the tank telling you it's tired.
6. Inconsistent temperature
Water that swings hot-to-cold can mean a failing thermostat, dip tube, or heating element — repairable on younger units, a bad sign on old ones.
7. Rising energy bills
A scaled-up, inefficient heater works harder for the same hot water. If your gas or electric bill crept up with no other explanation, the water heater is a prime suspect.
What To Do
Repair it or replace it?
The rule of thumb: under 8 years old with a single failed part, repair usually wins. Over 10 years old — especially with rust, base leaks, or chronic noise — replacement is the smarter money. Our approach is always repair-first on units with life left; we'll show you both quotes in writing so you can see the math. Start with our water heater repair service for an honest diagnosis.