How Long Do Water Heaters Last?

A typical tank water heater lasts 8 to 12 years and a tankless unit 15 to 20 or more. Where yours falls depends on the type, your water and how it has been looked after.

Updated 2026-10-19

Water heater lifespan by type

Those ranges hide some important differences:

• Gas tank: about 8 to 12 years. The burner heats the bottom of the tank directly, and sediment that settles there creates hot spots that stress the steel and the glass lining.
• Electric tank: about 10 to 15 years. There’s no flame, so less heat stress, but the lower element can burn out more often when it’s buried in sediment.
• Heat pump (hybrid) tank: roughly the same tank life as an electric tank, with a compressor and fan on top that can sometimes be repaired or replaced on their own.
• Tankless (gas): 15 to 20 years or more. There’s no tank to rust through; the heat exchanger is the long-lived core, and most other parts can be swapped out.

Most published estimates fall somewhere between 8 and 15 years for tanks, so treat any single number as a midpoint, not a promise.

Why water heaters wear out

A tank water heater is a steel pressure vessel lined with a thin layer of glass (porcelain enamel). Over the years, hot water attacks every tiny flaw in that lining. Manufacturers fight this with an anode rod, a magnesium, aluminum or zinc rod screwed into the top of the tank that corrodes first and protects the steel. Once the anode is used up, the tank itself starts to rust from the inside, and a leak is usually only a matter of time.

The other big enemy is sediment. Calcium and magnesium in hard water drop out as the water heats and collect on the bottom of the tank. On gas models the layer insulates the water from the burner, so the steel underneath runs hotter; on electric models it can bury the lower element. Either way, efficiency drops and wear speeds up.

What shortens a water heater’s life

• Hard water. The more minerals, the faster sediment builds and the harder the anode works.
• Never flushing the tank. A once-a-year drain-and-flush removes most loose sediment.
• High water pressure. Street pressure much above 80 psi, or a closed plumbing system without an expansion tank, makes the tank flex with every heating cycle.
• High temperature settings. Water stored very hot speeds up corrosion and scale. Around 120°F (49°C) is the usual recommendation for most homes.
• Water softeners and anode type. Softened water is easier on the tank in some ways but can use up magnesium anodes faster. The anode should be checked more often on softened water.
• Hot locations. Tanks in attics or uninsulated garages in hot climates tend to fail sooner.

How to make a water heater last longer

1. Flush it once a year, more often with hard water. Attach a hose to the drain valve, turn off the heat source, and run water until it comes out clear.
2. Check the anode rod every three to four years and replace it when it’s worn down to the steel core wire. On a healthy tank, this is the single best life-extending step.
3. Test the temperature-and-pressure relief valve once a year. Lift the lever briefly and make sure it reseats without dripping.
4. Install an expansion tank if your home has a check valve or pressure-reducing valve, and keep house pressure at a sensible level.
5. Descale tankless units annually by pumping a descaling solution through the service valves, and clean the inlet filter screen.

Signs your water heater is near the end

• Rusty or discolored hot water (with clear cold water)
• Popping, rumbling or banging while it heats
• Water around the base, rust streaks on the jacket or a wet drain pan
• Less hot water than it used to provide, or a longer wait for it to recover
• Corrosion on the hot and cold connections on top

A leak from the tank body is the end: there’s no repair for a rusted-through tank. Leaks from the drain valve, the relief valve or the pipe fittings, on the other hand, are usually fixable.

How to find out how old your water heater is

The manufacture date is on the rating label, either printed outright or built into the serial number. Every major brand uses a different code. Bradford White uses letters, Rheem uses the month and year, and A. O. Smith uses the year and week. Our free lookup decodes them for you, and this guide covers what to do when the label is missing or unreadable.

Once you know the age, our guide to when to replace a water heater walks through repair-or-replace decisions.