How Long Does a Water Heater Last? Signs Yours Is Near the End

Typical lifespans

According to the US Department of Energy's Energy Saver guide to tankless water heaters:

• Storage (tank) water heaters last 10 to 15 years.
• Most tankless water heaters have a life expectancy of more than 20 years, and they have easily replaceable parts that may extend their life further.

Those are typical ranges, not guarantees. Water quality, how hard the heater works, installation quality and maintenance all move the number up or down. The warranty length on the label is a rough hint at what the manufacturer expects, but it isn't a prediction.

How to find your water heater's age

1. Find the rating plate, the label on the side of a tank or the front of a tankless unit. It lists the brand, model number and serial number.
2. Check for a printed manufacture date. Some labels show it directly.
3. If not, decode the serial number. Many manufacturers encode the month and year of manufacture in the serial number, often as a letter or digits for the month and two digits for the year near the start. The format varies by brand and has changed over time, so look up your brand's decoding guide on the manufacturer's website or call their support line with the serial number.
4. Check paperwork. A home inspection report, a permit record or the previous owner's receipts may give the install date, which can be a few months after manufacture.

Signs a water heater is near the end

Ranked roughly from most to least serious:

1. Water leaking from the tank itself. A tank that leaks from its body, rather than from a fitting or valve, can't be repaired. Plan on replacement. See water heater leaking from the bottom to tell a tank leak from a fixable valve or fitting leak.
2. Rust-colored hot water (with cold water clear), which can mean the inside of the tank is corroding.
3. Rust or corrosion on the tank, especially around the base or the inlet and outlet connections.
4. Rumbling, popping or banging as it heats. That's usually sediment on the bottom of the tank; it makes the heater work harder and can shorten its life.
5. Less hot water than it used to make, or water that isn't as hot. That can be a fixable part, like a heating element or thermostat, but on an older tank sediment is often part of the story. See water heater not heating.
6. Age alone. A tank past 10 years with any of the signs above is a good candidate for planned replacement.

How McKinney's hard water affects a water heater

When water is heated, dissolved minerals come out of solution and settle as scale and sediment. In a tank, sediment builds up on the bottom, over the burner on a gas unit or around the lower element on an electric one. In a tankless unit, scale coats the heat exchanger.

Flushing and maintenance

The Department of Energy's storage water heater guide says routine maintenance, depending on your model, may include:

• Flushing a quart of water from the tank every three months
• Checking the temperature and pressure relief valve every six months
• Inspecting the anode rod every three to four years

The anode rod is a metal rod inside the tank that corrodes so the tank lining doesn't. Once it's used up, the tank itself starts to corrode, so replacing a worn anode can help an otherwise healthy tank last longer.

For tankless heaters, follow the manufacturer's descaling instructions. DOE notes that periodic maintenance can significantly extend a water heater's life, and says to check your owner's manual for specifics.

Flushing a very old tank that has never been flushed can stir up sediment and sometimes reveal a leak at the drain valve. If yours is old and has never been maintained, ask a plumber whether flushing is still worth it.

Tank vs tankless when it's time to replace

Using DOE's figures:

• Lifespan: tankless typically lasts longer (more than 20 years vs 10 to 15).
• Upfront cost: tankless costs more to buy and install. DOE says longer life and lower operating costs could offset the higher price.
• Efficiency: DOE says tankless models can be 24% to 34% more energy efficient than conventional storage tanks for homes that use 41 gallons or less of hot water a day, and 8% to 14% more efficient for homes using around 86 gallons a day.
• Flow limits: DOE says tankless heaters typically deliver 2 to 5 gallons per minute, and a large household running a shower and dishwasher at once can stretch one to its limit.
• Maintenance: both need it. In hard water, descaling a tankless heat exchanger matters.

Switching from tank to tankless often involves changes to gas lines, venting or electrical service, which affects cost. Water heater replacement covers sizing and what a proper installation includes.

Permits in McKinney

The City of McKinney requires a permit to replace a water heater. Its home repairs permit page says to search "Water Heater" in the City's Citizen Self-Service portal. The installing plumber normally pulls the permit, so ask about it when you compare quotes.

What not to do

• Don't wait for a flood if your tank is well past 10 years and showing warning signs.
• Don't ignore a dripping T&P valve or plug it.
• Don't choose a quote that leaves out the permit or required safety items.
• Don't attempt gas or 240 volt work unless you're qualified.

DIY vs calling a licensed plumber

Checking the age, looking for leaks and rust, and flushing a small amount from the drain valve are reasonable homeowner tasks. Call a licensed plumber for anode rod replacement if you're not comfortable with it, any gas or electrical repair, a leaking tank, or a replacement. See water heater repair for common repairs and choosing a plumber for checking a license.

What to tell the plumber

• Brand, model and serial number (a photo of the label is ideal)
• Gas or electric, tank or tankless, and tank size
• The symptoms and when they started
• Whether it has ever been flushed or had the anode replaced