How Long Do Water Heaters Last?

How long do water heaters last? Find out what you can do to extend their life.

Are you looking to find out how long your water heater may last? Maybe you’re looking for a new unit, but want to choose the one that’s going to last the longest? Today, we’ll help you out.

Although water heaters are renowned for lasting beyond expectations, they don’t last forever. Knowing how long a water heater will last helps you budget accordingly. Plus, you can prepare to purchase a new one once yours starts showing some aging signs.

How Long Water Heaters Last on Average

Water heaters are generally not supposed to last much beyond 15 years. This, of course, depends on the type of water heater, power or fuel source, maintenance, and quality.

Gas Water Heaters

Gas storage tank water heaters are often the most favored type among homeowners. They’re generally considered the economic as well as ecological option. Unfortunately, however, their average lifespan is a few years shorter than other types.

Gas water heaters usually last anywhere from eight to 12 years. One of the most common reasons why they fail is corrosion. Gas units are incredibly vulnerable to corrosion once they age.

Inside the tank, there is something called an anode rod. Manufacturers include this to protect the inner lining. The anode rod works by attracting corrosive particles using a method called electrolysis.

But, the anode rod can only take so much. After a couple of years, it starts to corrode and can’t attract more particles. Unbothered, the particles drop to the bottom where they begin to work on the tank instead.

Eventually, the tank will start leaking, marking the end of its service life.

Electric Water Heaters

Electric storage tank water heaters work in similar ways as a gas-powered unit. Still, the average lifespan of an electric unit is 10 to 15 years, as opposed to eight to 12 like its gas counterpart.

Instead of using a gas burner to heat the water, an electric boiler utilizes heating elements. There are usually two such elements inside the tank. Much like gas boilers, these are also highly dependent on maintenance.

The heating elements are usually the culprits of heater failure as they collect sediment build up over time. So, it’s crucial to clean or replace the elements as sediment will eventually stop them from working effectively.

Tankless Water Heaters

Tankless water heaters are very different from traditional boilers. Rather than having a storage tank, they’re, well, tankless. The unit doesn’t hold or store any water and instead, works on demand (1).

As soon as you open the hot water tap, cold water circulates the unit, receiving heat from the heat exchanger. Because a tankless model doesn’t store water, it’s spared from the corrosive nature that water can have. So the average lifespan of a tankless is at least 20 years — some even reach their 30th anniversary!

When a tankless finally reaches its last stretch, it’s usually thanks to a leak in the heat exchanger. This often leads to corrosion and a replacement is due. Fortunately, this rarely occurs before the 15-year mark. This, of course, depends on the overall quality of the unit.

What Affects a Water Heater’s Lifespan

The typical lifespan of a water heater is at least 10 years, but a few factors can shorten this (2).

1. Improper Installation

Water heaters need proper installation. This doesn’t just mean wiring it correctly. Water heaters should also be placed in an upright position in a well-ventilated space.

A well-ventilated area is vital for your safety, as it will prevent carbon monoxide build-up. Poor ventilation can also dramatically shorten your appliance’s lifespan.

Another thing to consider is the risk of flood damage. Even though the interior of your unit is rust-resistant, the exterior isn’t. So, locating your water heater on the floor, where it’s likely to be exposed to floods, isn’t ideal.

Water will rust the coating as well as the pipes and lines. Eventually, your unit may rust out and will no longer be safe to use.

The best location for your water heater, therefore, is in an out of the way but accessible spot. “Accessible” means it should not be obstructed by anything. This helps with maintenance and also meets the requirements for fire and health-hazard safety.

Stay Safe

If you buy a gas unit, we recommend hiring a professional to do the installation. Proper ventilation and piping are vital for your safety.

2. Usage

Water heaters aren’t super machines that deliver great volumes of continuous hot water forever. They eventually wear out.

So, constantly running large quantities of water through your unit will push it to the limit. Over time, your boiler becomes susceptible to wear and tear. Plus, the corrosive effects of hot water take a toll as well.

3. Quality

This is something to look for before you purchase a new water heater. Most experts will recommend that you spend a little extra on quality — and for good reason. Unsurprisingly, cheap water heaters will likely need to be replaced within a few years.

Pricier models usually last a lot longer. If you’re lucky, they will pay for themselves through energy savings.

One telltale indication of good quality is a long warranty. The longer the warranty, the sounder the construction. Consider it a confirmation that the manufacturer stands behind their product’s quality.

Additionally, look for a water heater with thick insulation. It should have durable heating elements and porcelain or glass-lined casing. Other features such as a self-cleaning function can help reduce mineral or sediment buildup.

4. Infrequent Maintenance

If the area you live in has hard inlet water — frequent maintenance is essential (3). Hard inlet water can reduce the lifespan of a water heater significantly.

The higher mineral content also decreases the unit’s efficiency. Even in areas with softer water, mineral deposits are bound to be present at some point.

The best way to counteract this is by performing frequent maintenance on your unit. Flushing the system often will minimize any potential build up. Newer models provide you with the luxury of including a self-flushing function.

Four Signs Your Water Heater Needs Replacing

If you pay close attention, your water heater might give you some clues that its service life is coming to an end. If you know that your unit is in its second stage of life, look out for the following signs:

1. Strange Noises

Some water heaters will always make some kind of noise. But if you suddenly hear rumbling or banging noises, it’s time to have a closer look.

The noise is due to sediment build-up which is a common result of infrequent maintenance. The mineral buildup falls to the bottom where it hardens and creates a thick crust. So, when you use the unit, it will creak and bang.

2. Tinted Water

Tinted water is never a good sign. Whether it’s red or yellow, it is generally a sign of rust. It’s essential to determine where it’s coming from.

Turn on the cold faucet, and if it runs clean and clear, you know there’s rust in the water heater. There’s not much to do at this point besides replacing the unit.

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3. Lower Temperatures

If you notice your water heater is struggling to produce hot water, it’s near its end. It might be that the water isn’t as hot as it used to be or that the amount is much less. Either way, replace it before it stops completely.

4. Pooling Water

Water that’s pooling near the base of your unit generally means bad news. Sometimes it might just be a fitting or valve that needs tightening or replacing. However, if it comes from the tank, it’s an indicator of cracks and corrosion — a death sentence for water heaters.

How to Extend Its Service Life

Unless your unit is near the end already, there are some steps to take to extend its lifespan a bit. Here’s what you can do:

  • Check pressure-relief valve: This is here to prevent an explosion. Place a bucket by the discharge pipe and raise the lever for the valve. If water doesn’t come out, replace the pressure-relief valve.
  • Check anode rod: Drain the tank and check the anode rod. If it looks corroded, replace it immediately.
  • Remove limescale: Limescale can prevent your unit from working efficiently. Remove it by flushing the tank with undiluted white vinegar.
  • Flush sediments: As we said before, sediments are bad news for a tank. So, flush it frequently to remove any buildup (4).

Here to the End

A good water heater has the potential to last a decade or two. If you take good care of it, it might work even longer. How long it lasts also depends on the type — tankless units generally last measurably longer.

Look out for signs of corrosion and rust. Perform regular maintenance and be mindful of your water usage. Doing this may help your water heater perform better and longer.

How long did your former water heater last? We’d like to read your answer below and we’re happy to answer any further questions you might have.

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About the Author

Peter Gray

Peter has been a homeowner for 35+ years and has always done his own repair and improvement tasks. As a retired plumber, Peter now spends his time teaching others how they can fix leaks, replace faucets, and make home improvements on a budget.