How Long Does a Water Heater Last?

Next steps (at a glance)

If you only do 3 things:

  1. Find the age of your water heater.

  2. Watch for rust, leaks, or unusual noises.

  3. Plan replacement before failure, not after.

Urgency level: Medium
(Becomes High if there is active leaking or visible rust.)

Short answer

Most residential water heaters last 8–12 years.
Tankless water heaters often last 15–20 years, depending on water quality, usage, and maintenance.

What a water heater does (and why it matters)

A water heater stores and heats water for showers, sinks, laundry, and appliances. When it works properly, it’s easy to forget it exists. When it fails, the result is often sudden loss of hot water, interior leaks, or water damage.

Unlike many appliances, a failing water heater can damage floors, walls, and nearby systems if it leaks or ruptures.

Typical water heater lifespan

TypeTypical lifespanReplacement cluesTank (gas)8–12 yearsRust, leaks, reduced hot waterTank (electric)10–12 yearsBreaker trips, slow heatingTankless15–20 yearsError codes, scaling buildup

Age alone doesn’t mean failure is imminent, but once a unit passes its expected range, the risk of sudden failure increases.

What shortens a water heater’s life

Several factors can reduce lifespan:

  • Hard water and mineral buildup

  • Sediment accumulation inside the tank

  • Skipping routine flushing

  • High temperature settings

  • Heavy daily hot water usage

Sediment buildup is the most common cause of early failure in tank-style water heaters.

Warning signs your water heater is nearing the end

  • Rust-colored or cloudy hot water

  • Water pooling near the base of the unit

  • Popping, rumbling, or banging sounds

  • Inconsistent water temperature

  • Visible corrosion on fittings or tank seams

If you see active leaking, treat this as urgent.

What happens if you don’t replace an aging unit

  • Sudden tank rupture

  • Interior water damage

  • Mold risk from slow, unnoticed leaks

  • Emergency replacement costs

Many water heaters fail without warning once the internal tank wall weakens.

DIY-safe checks you can do

These checks are safe for most homeowners:

  • Read the manufacture date on the unit’s label

  • Inspect the area around the base for moisture

  • Listen for unusual noises during heating cycles

  • Check that the pressure relief valve is not dripping

Do not attempt gas, electrical, or internal tank repairs.

Look for moisture or rust around the base and fittings
Any moisture, even a small amount, means deterioration has started.

  • Listen for popping or rumbling sounds during heating
    This usually signals sediment buildup inside the tank.

  • Keep the temperature near 120°F
    Higher settings increase internal wear and mineral scaling.

  • Flush sediment annually if you have hard water
    This slows internal corrosion and helps the heater run more evenly.

If any of these checks raise concerns, scheduling a professional inspection is the safest next step.

Common mistakes

  • Waiting until the heater fails completely

  • Ignoring small leaks

  • Skipping annual flushing

  • Setting water temperature too high

Planned replacement is usually less disruptive and less expensive than emergency replacement.

When to call a professional

Contact a licensed plumber if:

  • The unit is leaking

  • Rust appears at tank seams

  • Hot water output drops suddenly

  • The unit is beyond its expected lifespan

What to ask:

  • Replacement options and sizing

  • Efficiency differences

  • Installation timeline

What to expect:
Replacement costs vary widely by region and unit type. Planning ahead typically reduces cost and downtime.

Related guides

Disclaimer:
This is general information only. When in doubt, hire a licensed professional.