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How often should you replace a water heater?

Updated July 2026

← All maintenance intervals

A standard tank water heater lasts 8 to 12 years, so start planning the swap around year eight rather than waiting for a cold-shower morning. Hard water and a neglected anode rod cut that short; annual flushing and a fresh anode stretch it. Replacing on your own schedule runs $1,500 to 2,500 installed and lets you skip the emergency premium, plus the water damage when a rusted tank finally splits open across the floor.

What changes the interval

How often should you replace a water heater? By situation, Updated July 2026
Your situation Interval Why
Standard tank, softened water 10–12 years Fewer minerals means slower tank corrosion
Standard tank, hard water, no anode care 6–10 years Scale and a spent anode rust the steel early
Tankless (on-demand) unit 15–20 years No standing tank to corrode, with annual descaling
Rust-colored hot water or a damp base Replace now The tank is already corroding through; rupture is close
Unit is 10+ years old Budget the swap Replace on your terms, not on a flooded floor
Popping or rumbling every heat cycle Flush, then plan Baked-in sediment signals the tank is near the end

The cost of skipping it

What skipping it costs: run a tank past its life and you are gambling on a rupture. When a corroded tank lets go, it can empty 40 to 50 gallons plus continuous supply onto the floor, and water damage in a finished space runs $2,000 to 10,000. An emergency same-day replacement also costs more than a planned one. Two habits buy years: an annual flush and a fresh anode rod. See the full failure cost breakdown before you gamble.

How to do it (Half a day · Pro install, $1,500–2,500)

  1. Note the manufacture date on the rating label (often encoded in the serial number); past 8 to 10 years, start planning.
  2. Watch for warning signs: rusty hot water, moisture or rust at the base, popping noises, or hot water that runs out fast.
  3. Decide on type: a like-for-like tank is cheapest; a heat pump or tankless costs more up front but far less to run.
  4. Get two or three quotes; installed prices vary widely by region and by whether venting or gas lines need work.
  5. Have the old unit hauled away and the new one strapped for seismic and fitted with a drip pan and drain if in a living space.
  6. Set the thermostat to 120°F and note the install date so the anode and flush schedule starts fresh.

Knowing the interval is the easy half. OnOtto reminds you at the right interval, and it won't let you snooze it into next year. Tasks persist until they're done, and completing water heater replacements schedules the next one automatically.

Put this on autopilot, free for 30 days

Frequently asked questions

How do I know when my water heater is about to fail?

The clearest tells are rusty or brown hot water, water pooling or rust streaks around the base, popping or rumbling when it heats, and hot water that runs out faster than it used to. Any moisture at the tank seam means the steel is corroding through and a rupture is coming. Once you see those, replace on your schedule this month rather than waiting for the tank to dump its contents onto the floor at 2 a.m.

Is it worth replacing a water heater before it breaks?

Past about 10 years, usually yes. A planned replacement lets you shop three quotes, pick an efficient model, and avoid the emergency-callout premium plumbers charge for same-day work. More importantly, it takes the rupture risk off the table, and one flooded floor can cost more than the heater itself. If your tank is in a finished basement or upstairs closet, the case for getting ahead of failure is even stronger.

Does a tankless water heater actually last longer?

Yes, typically 15 to 20 years versus 8 to 12 for a tank, because there is no standing reservoir of heated water to corrode from the inside. The trade-off is higher up-front cost and a firm annual descaling requirement, which many manufacturers make a warranty condition. In hard water, skipping the descale scales up the heat exchanger and erases the longevity edge, so a tankless only outlives a tank if you actually keep up with the flush.

What temperature should I set my water heater to?

120°F is the standard recommendation: hot enough to keep bacteria like Legionella in check and to run dishwashers, cool enough to prevent scalding and to slow tank corrosion and scale. Every 10 degrees higher also raises standby energy loss. Homes with immune-compromised residents sometimes run hotter and add a mixing valve at the fixtures for scald safety. Turning it down from 140 to 120 both saves energy and buys the tank extra years.

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