Quick answer
A tank water heater commonly lasts about 8 to 12 years, and a tankless unit often 20 years with descaling. Hard water, skipped flushing and a spent anode rod shorten that. Find the age in the serial number on the label, where most brands encode the year and month. Warning signs are rusty hot water, rumbling or popping, water around the base and less hot water than before. A tank near the end of its life is worth replacing before it leaks; replacement runs about $900–$4,500 installed by type. Call (888) 217-6781 to reach a plumbing company taking calls in your ZIP.
Follow the short menu, then your 5-digit ZIP. The line goes quiet for a few seconds while it connects; stay on. If it does not connect, call once more: companies taking calls change minute to minute.
Written & reviewed by Marcus ReedIICRC WRT
Reviewed November 4, 2026· Next review May 2027
Water heaters fail on a schedule more than most appliances, because the steel tank corrodes from the inside at a rate set by the water and the maintenance. Knowing the age of yours tells you whether a small problem is a repair or the start of the end.
Typical Lifespan
| Type | Common lifespan | What shortens it |
|---|---|---|
| Gas or electric tank | about 8 to 12 years | Hard water, sediment, a spent anode rod, high pressure |
| Tankless | often around 20 years | Scale in the heat exchanger without descaling |
How Old Is Yours?
The serial number on the rating label usually encodes the manufacture date. Many brands put the year and month in the first four characters, as numbers or letters. Search the brand name with "serial number date" to read your format, or ask a plumber. The installation date on a permit or a sticker is the other clue.
Warning Signs
- Rusty or brown hot water while the cold runs clear. See brown water from the faucet.
- Rumbling or popping while heating: heavy sediment. See water heater making noise.
- Moisture, rust or a stained pan at the base. See water heater leaking from the top or bottom.
- Less hot water than it used to give.
- A relief valve that drips. See water heater expansion tank.
Talk to a plumber about this
One call reaches a plumbing company taking calls in your ZIP.
What Extends It
- 1Flushing sediment from the tank, often once a year.
- 2Checking the anode rod every few years and replacing it when worn.
- 3Keeping house pressure in range and adding an expansion tank on a closed system.
Repair or Replace
Valves, elements and thermostats are repairable. Water coming from the tank itself is not. On a tank near or past 10 years with any of the signs above, replacement before it fails usually costs less than the cleanup after. Valve or fitting repairs run about $100–$400; replacement about $900–$4,500 installed by type. Compare in water heater repair or replace and tankless vs tank.
The Call
Call when the tank is near the end of its life and showing signs, or for a replacement quote. (888) 217-6781 connects you to a plumbing company taking calls in your ZIP. Follow the short menu, enter your 5-digit ZIP and stay on while it connects; if it does not connect, call once more, because the companies taking calls change minute to minute.
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Frequently Asked Questions
How long do water heaters last?
Tank models commonly last about 8 to 12 years; tankless units often around 20 with regular descaling. Water quality and maintenance change this a lot.
How do I tell how old my water heater is?
Read the serial number on the rating label. Most manufacturers encode the year and often the month in the first characters; the brand's website explains its format.
Should I replace a water heater before it fails?
A tank past about 10 years that shows rust, rumbling or moisture at the base is a good candidate, because a tank that fails can release its whole contents onto the floor.
Can a water heater last 20 years?
Some tanks do, usually with soft water, regular flushing and anode rod replacement. Tankless units reach 20 years more often.
Sources
- U.S. Department of Energy: storage water heaters
- U.S. Department of Energy: tankless or demand-type water heaters
Methodology: How we source and verify data · Report an error
Disclaimer: HearthDry is an independent educational resource. This article is for informational purposes only and does not constitute professional, legal, or insurance advice. Consult licensed professionals before making decisions about your property or insurance claims.