When Should You Replace a Water Heater?

Because a water heater doesn’t need a lot of attention, it can be easy to forget about until something goes wrong. That’s why it’s important to know how to maintain this essential plumbing fixture, and when to replace it. How long a water heater lasts depends on the type of unit, its age, maintenance and water quality in your home.

Quick takeaway: If your unit is getting older, showing signs of corrosion or leaking, it may be time to start planning for replacement before water damage becomes a bigger problem.

The average life of a water heater

How long do water heaters last? That depends on the type you own, its age, how well you maintain it, water quality and how often you use it. People often use “water heater” and “hot water heater” to mean the same appliance.

If you’re specifically asking how long do tankless water heaters last, many tankless models can outlast standard tank systems, but their life span still depends on maintenance and usage.

Also called “on-demand” water heaters, tankless systems heat water only when needed, which can make them more efficient than the tank style.

When you buy a home, ask the previous owner the water heater’s age so you can plan and budget for a new one. Or, you might be able to determine how old it is by checking the serial number. Normally, you’ll find that information on the top of the equipment, and it begins with a letter and series of numbers. The first letter may stand for the month it was made (A for January, B for February). The next two numbers can tell you the year it was manufactured. For example, C18 may stand for March 2018.¹ When in doubt, check with the manufacturer.

How to make your water heater last longer

Regular maintenance is the key to keeping the hot water flowing in your home.²

For a traditional tank:

• Every six months: Flush the tank to remove sediment that’s built up inside. Attach a hose to the valve at the base of the unit. Then flush the water outside or to a nearby drain. Be sure to turn off the heater’s power first.
• Every year: Have a professional plumber inspect the heater. They’ll check for broken valves and loose or wet joints, as well as rust.
• Every two years: Most traditional tanks have an anode rod that protects the interior lining by attracting all corrosive particles to itself. As the rod ages, it no longer collects those rust-causing materials, and they end up on the bottom of the tank, where they may eventually destroy the lining. Check the rod to see whether it needs to be replaced.

For a tankless heater:

• Every year: Have a professional plumber inspect the venting system, burner (if gas), pressure relief, water filter and more.
• Every two years: If your model has heating coils, have them professionally cleaned.

Keeping your water heater running efficiently ensures you have hot water whenever you need it, and helps avoid higher-than-normal energy bills. For more comprehensive tips on maintaining your home's plumbing system, including your water heater, check out our guides on preventive plumbing tips and telltale signs of a water leak.

When to replace a water heater

Water heaters last until there’s corrosion on the inside. When that happens to yours, it’s on its way out.¹ Here are the signs you need a new one:

• Banging noises. Thick calcium sediment on the inside of the tank can cause the unit to make noises.
• Cold water. If your hot showers are shorter than usual, it may mean the fixture can’t heat up as efficiently as it used to.
• “Rusty” hot water. Hot water that looks a little red or orange may be a sign of rust in the water. Keep in mind, this applies to hot water only. If it also happens when you turn on the cold water, that suggests another issue.
• Funny smell or taste. Hot water may taste metallic, or smell like rotten eggs.
• Leaks. Call a plumber. A professional can tell whether your water heater has failed or you have a different problem. If it has failed, it’s probably due to a crack in the tank.
• Higher energy bills. Spikes in your energy costs may mean your appliance isn’t working efficiently. If changing the temperature on it doesn’t work, there may be a deeper problem.¹
• When deciding when to replace a water heater, warning signs matter just as much as the unit's age. An older system that’s leaking or losing efficiency may be nearing the end of its useful life.

Location can also affect your heater’s life span. A system located in a garage or crawl space, where the temperature drops significantly, will have to work harder to heat the water. As a result, it will tend to wear out more quickly than a unit inside a temperature-controlled house. If your appliance is located in one of these areas, look for end-of-life signs earlier than the manufacturer recommends.

How much does it cost to replace a water heater?

What you pay to put in a new water heater will depend on the type and size, as well as the expense of professional installation. The estimated average cost for a tank style runs from $650 to $2,500,³ which includes labor and materials. This type holds anywhere from 30 to 80 gallons, with a 40-gallon tank being the most common. While a 40-gallon size is enough for a two-person household, a 60- to 80-gallon tank may be better if you have more than five people in your home. Here’s a breakdown of estimated costs based on size:

• 30 gallons: $550 to $2,100
• 40 gallons: $550 to $2,350
• 50 gallons: $650 to $2,500
• 75 gallons: $1,250 to $3,500
• 80 gallons: $1,350 to $3,500³

For a tankless appliance, you could spend from $1,200 to $3,500 (including labor and materials).³

The brand you choose will also make a difference. Many now come with built-in smart features that guard against damage by detecting leaks and automatically shutting off the water. Some also monitor water usage, and let you control the temperature and other settings from your mobile device.⁴ In addition, some insurers partner with manufacturers to offer savings when you buy one.

Does homeowners insurance cover my water heater?

While most standard homeowners policies won’t pay to repair or replace a leaky water heater, they may cover damage the leak causes. It all depends on the insurance company’s review and details of the loss. Coverage often depends on what was damaged and how the loss happened. Avoid this problem by keeping up with maintenance or replacing your water heater when the time comes.

Planning for it now will ease the expense of replacing your water heater. Keep track of its age, and perform regular maintenance to help extend its life. Regular maintenance helps your unit last longer and can prevent major water damage.

Plan your next steps

Knowing the life span of your water heater helps you plan for its eventual replacement and avoid unexpected disruptions. If your water heater is nearing the end of its typical life span, consider scheduling an inspection or researching replacement options. You can also learn when you should replace appliances for other home maintenance planning tips.