How long does a water heater last? According to the U.S. Department of Energy, most tank water heaters last 10 to 15 years, and tankless water heaters can last more than 20. Where yours falls in that range depends on your water, how hard the heater works, and whether it’s ever been maintained. If your tank is past ten years old, it’s worth knowing the warning signs before it fails on its own schedule.
Key takeaways
- Tank water heaters: most last 10 to 15 years. Tankless: more than 20, per the Department of Energy.
- Sediment is the main thing that shortens a tank’s life, and hard water makes it build faster.
- Rusty hot water, rumbling or popping, and moisture around the base are the signs to take seriously.
- You can find the age on the rating label. The serial number usually encodes the manufacture date.
- A tank failure is a flood. If yours is in a finished basement or a closet, plan the replacement before it leaks.
How to tell how old your water heater is
Look for the rating label on the side of the tank. Many manufacturers build the month and year into the serial number, often as a letter and number or as the first four digits. The exact format varies by brand, so if you can’t read it, search the brand name with “serial number date,” or have us look at it during a visit. If the house came with the water heater, assume it’s at least as old as your time in the home.
What wears a water heater out
Inside a tank water heater, minerals in the water settle to the bottom as sediment. Over time that layer insulates the water from the burner or element, so the heater works harder and the tank runs hotter at the bottom. That’s what makes the popping and rumbling noise many older tanks have. Where water is hard, the sediment builds faster.
Most tanks also have an anode rod, a metal rod that corrodes so the steel tank doesn’t. Once it’s used up, the tank itself starts to rust from the inside. Flushing sediment and checking the anode rod are the two maintenance steps that make the most difference to how long a tank lasts. Most tanks never get either.
Tankless heaters don’t store water, so they don’t rust out the same way. They still collect scale in the heat exchanger, and in hard-water areas they benefit from periodic descaling.
Signs your water heater is near the end
- Rusty or discolored hot water. If it’s only the hot side, the tank may be corroding inside.
- Rumbling, popping or banging as it heats. That’s heavy sediment.
- Moisture, drips or rust at the base of the tank or around the fittings.
- Hot water that runs out faster than it used to, or takes longer to recover.
- Age. A tank past ten years old with any of the signs above is on borrowed time.
If you already see water on the floor, start with our guide on what to do when your water heater is leaking. It covers shutting off the water and power or gas, and how to find where the leak is coming from.
Why it pays to replace before it fails
A water heater rarely fails at a convenient time. When a tank lets go, it can put a lot of water on the floor before anyone notices, and many shore homes have the water heater in a finished basement, a utility closet or a garage next to living space. Second homes are the riskiest of all, since nobody may be there to see it for weeks.
Replacing a tank on your schedule means you can choose the replacement instead of taking whatever is on the truck. That’s the time to decide between another tank and a tankless unit. Our post on the pros and cons of tankless water heaters lays out the trade-offs, and you can see a tankless install we did in Wall Township.
If you’re keeping your current tank for now, a leak protection device adds a layer of protection. We install the LeakBreaker, which uses a sensor and a valve to shut off the water supply when it detects a leak from the water heater.
How to get more years out of the next one
- Have the tank flushed periodically to clear sediment, more often if your water is hard.
- Have the anode rod checked and replaced before it’s gone.
- Keep the area around a gas water heater clear so it gets the combustion air it needs.
- Have tankless units descaled on the schedule the manufacturer recommends.
The Department of Energy’s Energy Saver Guide covers water heater types and efficiency if you’re comparing options.
Not sure how much life your water heater has left? Rostron Premium Home Services handles water heater repair and replacement, tank and tankless, for homes across Monmouth and Ocean County. Call 732-374-9949 or see our plumbing services.
