When should a water heater be replaced instead of repaired?

Replace when the tank is over 10 years old, the tank itself is leaking, or you're on the second major repair. A leaking tank cannot be repaired — the steel has corroded through, and it will only get worse.

What water heater repairs are worth doing?

On a unit under 8 years old, a bad thermostat, heating element, thermocouple, or pressure-relief valve is a cheap fix worth making — usually $150–$400. The tank is fine; a component failed.

What's the difference between a leaking tank and a leaking fitting?

A leak at a pipe fitting or valve on top is repairable. Water pooling under the tank, from the body of the tank, means internal corrosion — replace now, before it floods.

How long does a water heater last?

Tank (gas or electric): 8–15 years. Tankless: 15–20 years. After year 10, a tank is on borrowed time; plan the replacement before it fails on its own schedule.

What does water heater replacement cost in 2026?

Standard tank (40–50 gal): $1,200–$2,500 installed. Tankless: $3,000–$6,000 installed. A planned swap costs the same unit without the emergency plumber premium or the water damage.

Repair or replace your water heater?

Water heaters give you one of two kinds of failure: the cheap kind, where a $200 part restores hot water, and the expensive kind, where the tank itself has rusted through and there's water on your floor. Telling them apart is the whole decision.

The one question that settles most cases: is the tank leaking?

Look at where the water is coming from.

Leaking from a fitting, valve, or pipe on top: repairable. A connection loosened or a valve failed; the tank is fine.
Water pooling under the tank, seeping from the body: the steel has corroded through. This cannot be repaired. Replace now, before it lets go and floods the space.

A leaking tank only gets worse. There is no patch — the metal is gone.

The age test

Tank water heaters last 8–15 years; tankless units 15–20.

Under 8 years: repair. At this age a failure is almost always a component, not the tank.
8–12 years: repair small things; start budgeting for replacement.
Over 12 years: replace on the next real failure. You're past the point where repairs are a good bet.

Repairs worth making on a younger unit

If the tank is sound and the unit is under about 8 years old, these are cheap fixes — usually $150–$400 — and worth doing:

Failed thermostat or heating element (electric)
Bad thermocouple or pilot assembly (gas)
Leaking pressure-relief valve or drain valve

Warning signs it's near the end

Rusty or discolored hot water, rumbling or popping from sediment, hot water running out faster than it used to, or any moisture at the base. Read more in our water heater and sewer lateral guide.

What replacement costs in 2026

A standard 40–50 gallon tank runs $1,200–$2,500 installed; tankless runs $3,000–$6,000. A planned swap costs the same unit — without the emergency-plumber premium or the water-damage cleanup. See our methodology for how we estimate ages and costs.

The bottom line

Leaking tank or over 12 years old → replace. Sound tank, under 8 years, isolated part → repair. The goal is to replace on your schedule, not on the day the tank finally gives out. Knowing its age is what makes that possible.

Also worth reading: repair or replace your furnace and how to budget for home maintenance.