How Long Does A Water Heater Last? Tanked & Tankless Covered.

Researched & Written by Craig

“I’ve set this water heater to max settings. But why does it still feel so cold?”

“Sorry to hear that, friend, but your heater’s probably broken.”

“Already?! Just how long does a water heater last?!”

Ever asked that question? Well…

Different types of water heaters have different average lifespans.

Water Heaters - Average Lifespan by Type
TankedTanked Gas Water Heater8 to 12 years
Tanked Electric Water Heater10 to 15 years
TanklessTankless Gas Water Heater20 years
Tankless Electric Water Heater20 years

But the actual lifespan of your water heater depends on usage and care.

Want to know the details?

Read on.

How Long Do Tanked Water Heaters Last?

There are 2 major types of water heaters: tanked and tankless.

A tanked water heater uses…well, a tank. While a tankless water heater doesn’t.

Tanked water heaters keep the hot water…in the tank. They are what you call traditional water heaters or conventional water heaters.

Typically, tanked models will have a shorter lifespan than tankless ones.

Why? That’s mostly because…there’s a tank!

You see…

Chemicals and minerals in the water can leave deposits on the bottom of the tank.

These will:

  • Build up sediments over time
  • Cause rust and corrosion in the tank
  • Cause leakage in the tank

Which leaves a tanked water heater to last for only so long.

How long? Well, it may depend on what powers the heater. And there are 2 other types of tanked heaters based on the power source: gas and electric.

Gas Tanked Water Heaters

Gas or propane tanked water heaters last for about 8 to 12 years. The most common thing that limits their life is corrosion.

A gas water heater’s ‘downfall’ often begins when the anode rod fails to do its job.

You see, a tanked gas water heater has this part called the anode rod. It protects the tank’s interior lining. This rod prevents corrosion by attracting corrosive particles to itself, sacrificing its life for the sake of the tank.

(Which is why it’s also called a ‘sacrificial anode rod.)

Over time, this anode rod becomes too corroded. When this happens, it can’t attract corrosive particles anymore. The particles then drop to the bottom of the water tank. They begin eating away at the tank lining, causing leaks in the long run.

Somehow, though, you can extend the life of your tanked water heater by replacing the anode rod every 1 to 2 years.

Electric Tanked Water Heaters

Meanwhile, an electric tanked water heater can last for about 10 to 15 years. That’s a little longer than their gas-powered counterparts.

Their advantage? Hmmm… not really much. Electric tanked water heaters also have an anode rod. Plus, gas and electric tanked water heaters work in almost the same way.

The main difference is that an electric model uses electric heating elements to heat up your water. (Gas heaters heat the water through a gas burner.)

Sooo… electric heaters mostly have fewer parts to use and maintain. This would likely contribute to the longer lifespan of electric-powered heaters.

Comparing the parts of tanked water heater types: gas-powered vs electric water heaters. Source: Landmark Home Warranty

How Long Do Tankless Water Heaters Last?

Tankless water heaters, whether electric or gas-powered, can last for about 20 years.

That’s waaay longer than a tanked model. And you might already have a clue why.

It’s about the design.

The more modern tankless models only receive water the moment you turn a hot water tap on. They don’t store hot water in a tank. So goodbye, too-much-sediment-build-up!

Still, tankless water heaters have a heat exchanger. Over time, it develops leaks, and leaks lead to corrosion.

Good thing these leaks only start to appear when your tankless heater reaches the age of 15. Typically.

With proper care, tankless water heaters can keep on functioning well for as long as 30 years.

When Should I Replace My Water Heater?

Want a quick answer?

  • Best time: 2 years before it reaches its expected lifespan. (You can get a more efficient model and save yourself maintenance costs and bills!)
  • Otherwise: If you can’t help it, it’s when your water heater already shows the following signs of ageing:

Signs to Look For

If you spot 3 or more of these signs, then you better start looking for a new water heater.

Water Remains Lukewarm or Cold

You’ve maxed out the settings, but the water’s still lukewarm. Sometimes, it’s just purely cold. Or, it may start out hot, but then it goes lukewarm later.

Here’s the thing.

If your tank is full, or if no other appliance is using up your hot water, then you know something’s wrong. Either you didn’t get the proper water heater size, or the heater’s busted.

And if you did get the correct water heater size…

The problem’s likely in the heating element. Or, it could also be in the electric thermostat, or perhaps the dip tube. These parts can simply fail over time. You can replace these parts or buy a new heater entirely.

Strange, Gurgling Noise

Near the end of your water heater’s lifespan, you’ll likely hear a rumbling or banging noise while it’s on.

What’s causing this noise? It’s the sediment build-up in the tank. The sediment also heats up and bursts, causing some gurgling or creaking sounds when you’re using the water heater.

Dirty Water

Does red, brown, or yellowish hot water come out sometimes? That could mean rust.

But… what if you also get the same ‘tint’ when running on cold water? In that case, your galvanised piping could be the one rusting.

Leakage

Does water pool around the base of your water heater tank? Check if the leak only comes from a fitting or a valve. (If yes, then simply tighten the valve.)

But if the leak comes from the tank itself, it may have cracks. Worse, it may have corroded parts inside.

Drain Valve Not Draining Anymore

Sediment build-up can also clog your water heater’s drain valve. This keeps the drain valve from draining water.

And if your heater’s drain valve is no longer draining water, then it’s probably time to find a new heater.

Age

Ultimately, you can get a clue from your water heater’s age. How old is it now?

10 years and still doing great? You’re quite a keeper.

15 years? Man, excellent maintenance work!

But probably, you owe it a lot to your heater’s type. (Remember what we discussed above?)

Point is, your heater’s age can only confirm either one of two things (or even both):

  • How good your heater is.
  • How amazing you are at maintaining it.

So, if it’s 18 years old and still running, then you and your heater are doing a great job. And you’re likely using a tankless water heater. It’s performing as expected.

But if your water heater has already hit the 10-year mark, and all you’re getting are cold showers, then…

It’s probably time to replace it. And aren’t you using a tanked water heater? If so, the age only confirmed the case.

Corrosion, wear and tear likely took over. And a replacement will probably save you more money than any attempt at repair.

Tips for Maintaining a Water Heater

You’ve probably noticed one major water heater ‘enemy’ by now. It’s sediment build-up!

While sediment, rusting, and corrosion will eventually take over and ‘kill’ your water heater, you can fight them off. Take note of the following tips to help extend the life of your water heater.

  1. Flush your water heater once a year. This will help remove the sediment and prevent damage to your water heater tank. (If you can, it’s even better to do this 2x a year.)
    And when you do, keep flushing the water until you’ve taken out all sediments. It might take you 2 to 3 gallons of water to accomplish this.
  1. Remove limescale. Limescale refers to the white, chalky deposit you’d often find in your fixtures. (You may see some in your washing machine, or even in your kettle!).
    One really cheap cleaning agent is white vinegar. Here’s how to apply it:

Removing limescale for tanked heaters:

    • Slightly open one of your faucets.
    • Attach a hose to the drain valve.
    • Turn off the cold water supply.
    • Remove some of the water inside the tank.
    • Turn off the faucet.
    • Remove the anode rod.
    • Pour in the white vinegar.
    • Put the anode rod back (Tip: you can also replace it with a new one!)
    • Turn on the cold water supply.
    • Leave the vinegar in the tank for about 6 hours.
    • Drain all the liquid content in the tank.
    • Refill the tank with water.

Removing limescale for tankless heaters

    • Remove the lid.
    • Close the 3 water valves.
    • Remove the valve caps.
    • Attach hoses to the valves, one for each.
    • Reopen the valves.
    • Flush your water heater with white vinegar.
    • Place the valve caps back.
    • Remove the filter.
    • Rinse the filter with water.
    • Place the filter back.
    • Put the cover back.
    • Restart your water heater.

Note: In any case, please review the manufacturer’s manual and follow the safety procedures there!

Effects of Water Quality on a Water Heater

We talked about how minerals and chemicals in your water can leave sediments in your water heater’s tank. You’re lucky if you have a supply of soft water and not hard water.

  • Soft water means less dissolved minerals.
  • Hard water means more dissolved minerals.

Hard water tends to reduce the life of your water heater by 2 or more years.

Here’s some good news. You can use a whole-house water softener to change your water quality.

Generally, a water softener can double the lifespan of a water heater.

Troubleshooting Common Water Heater Issues

Your water heater could still be young, but it’s already acting up. Here’s how you can troubleshoot its most common issues.

Check the following parts:

  1. Pressure-relief valve. Tanked or traditional water heaters have this valve. To test:
    1. Place a bucket under its discharge pipe.
    2. Raise the valve’s lever.
    3. If water comes out of the pipe, it’s all good.
    4. If not, you need to replace this pressure-relief valve.
  2. Anode rod. You can find this rod screwed to the top of your tanked heater.
    1. Any sign of corrosion?
    2. If yes, replace this rod immediately.
  3. Gas lines. You’ll have these in a gas water heater.
    1. Are there signs of corrosion?
    2. Are there cracks?
    3. Any leaks?
    4. If you said yes to any of these questions, call for help. A professional HVAC service should be able to help you. Note: Even a small leak can be dangerous!

Conclusion

Tanked water heaters can last for about 10 years, while tankless ones can stay useful for 2x longer (20 years). With proper care, some tankless water heater models can even reach age 30.

In any case, water heaters ‘die’ because of sediment build-up, rusting, corrosion, and broken parts.

The good news? You can extend the life of your water heater with regular maintenance. Do some troubleshooting. Perform flushing and draining. And replace your heater’s vital parts, such as the anode rod.

Sometimes, though, it’s best to let go of your old heater as it approaches its expected end. Take advantage of the latest models, pick the water heater with the correct size, and replace your current heater.

Do this 2 years before your unit turns crazy. You could reduce your utility costs and even enjoy a warm dip without shivering from time to time.

Thanks for reading, and have a lovely day!

– Craig