How Long Do Water Heaters Last? Signs & Cost to Replace


Water Heater

Water heaters are a very important part of our everyday lives. We use water heaters every day and often take advantage of them providing hot water when we need it. Often times we don’t prepare for replacement and when a water heater quits it can become a shock to us and our wallet. 

Part of being able to prepare and budget for a water heater replacement is knowing how long a water heater will last.

So, how long does a water heater last? The typical lifespan of an electric water heater is 10 to 15 years. A gas water heater has a shorter lifespan of 8 to 12 years on average. Tankless water heaters can last up to 20 years. 

Do you need a Licensed Plumber? We can help!
Get a free estimate from top-rated, screened, and licensed plumbers in your area!

Can a water heater last 20 years? A well-maintained gas or electric water heater can last up to 20 years or more provided the water heater has been properly maintained. This includes the replacement of the anode rod every 2-3 years to protect the inner lining of the tank to keep it clean and in good condition.

In this article, we will focus on tank-style gas and electric water heaters. There are many factors that go into determining how long a water heater will last. The number one factor that can extend the water heater’s lifespan is water heater maintenance.

Many of these factors have to do with proper maintenance which if done routinely can extend the life of a water heater several years. However, if the water heater is not maintained well you can expect the lifespan to be shorter and you could risk sudden failure or worse damage to your house. 

Even inexpensive water heaters can outlast more expensive models provided it’s properly maintained.

Most inexpensive water heaters come with a 6-year manufacturer warranty. However, some better quality models can have manufacturer warranties upwards 10 to 12 years. While some high-end models can have lifetime warranties on the water heater. 

Water heaters with a fiberglass tank tend to last considerably longer than water heaters with steel tanks. Regardless of type, it is important to remember that all tanks eventually fail no matter how well it’s maintained. 

Why Tank Water Heaters Fail

A water heater may seem to fail out of nowhere, but that’s not the case. Water heaters fail over time. It is recommended you drain and flush your water heater annually as part of your home maintenance schedule. You should also replace your anode rod inside the water heater every 2-3 years. This sacrificial rod protects the lining inside the tank.

Water heater failure can often be predicted if you are aware of the signs. There are two main reasons why tank-style water heaters fail. These two reasons are:

Too much pressure inside the tank 

As the water heats up it expands. This is expansion creates pressure inside the tank. If the water inside the tank heats up to a point that it exceeds the tanks pressure specification the tank could rupture. One of the ways to avoid this is keeping your hot water temperature under 140°F.

Modern water heaters are equipped with a safety feature called a temperature and pressure relief valve (T&P valve). The temperature and pressure relief valve opens when the pressure inside the tank reaches the tank temperature threshold. This valve will expel hot water through a discharge pipe to the exterior of the house to relieve the pressure inside the tank.

Another safety feature that can be added is an expansion tank. Expansion tanks help control pressure inside the water heater tank by providing a place for hot water to expand. In a 50 gallon tank, hot water expands to 52 gallons. A 2-gallon expansion tank can store the expanded water. 

One of the problems with older water heaters is they lack a T&P valve and an expansion tank to help control the pressure inside the water heater. With nowhere to go pressure inside the tank can cause the water heater to explode turning many older water heaters into a ticking time bomb.

Sediment Buildup Inside the Tank

The second leading cause of water heater failure is sediment buildup inside the tank. Chemicals and contaminants found in the water supply cause corrosion inside the tank which will eventually rust out the tank causing it to leak.

Once a flaw develops inside the tank, the pressure inside the tank builds and forces water through these weak areas inside the tank. 

Water heaters with glass liners are equipped with an anode rod. The water heater anode rod attracts contaminants in water. Over time the contaminants will eat away at the anode rod rather than the tank.

The anode rod, in essence, sacrifices itself to protect the tank. Anode rods will last 3-5 years depending on the quality of the rod. 

Once the anode rod is eaten away there is nothing left for settlement and contaminants to attack other than the tank itself. 

How to Maintain Your Water Heater

water heater

Drain and Flush Your Water Heater

As part of your annual maintenance on your water heater, you should drain the tank and flush out any sediment inside the tank. Tank water heaters have a drain valve at the base of the tank to do this.

Here’s a quick rundown of how you can drain and flush your water heater 

  1. Turn off the water supply before working on the water heater.
  2. Turn off power or gas to the water heater before starting work.
  3. Attach the hose to the drain valve and run it to the exterior to drain freely and safely. Remember the water will be hot.
  4. Open hot water tap at a nearby sink.
  5. Open the drain valve on the water heater to begin draining.
  6. Once the water heater has drained, turn the water supply back on the flush the tank.
  7. Close the drain valve once the water heater has been flushed and water running from the hose is clear.
  8. Allow the water heater tank to refill.
  9. Turn the power or gas back on to the water heater back. If you have a gas water heater, you’ll likely need to light the pilot.

Replace Your Anode Rod

The tanks inside most water heater are made from steel. The steel tanks have a thin glass lining to protect the metal from corrosion. As the water heater ages, the glass develops cracks. Once the glass lining cracks, water starts to corrode the steel tank. This is where the anode rod steps in as a secondary line of defense.

The anode rod is a long metal rod inside the water heater that attracts corrosive elements in the water. Over time, typically 3-5 years, the anode rod will corrode to a point where it can no longer defend the water heater.

Once the anode rod has become so corroded that it can no longer do its job, the tank itself begins to rust. The good news is, if caught early, you can replace the anode rod and nearly double the lifespan of your water heater.

Anode rods are made from magnesium, aluminum or aluminum/zinc alloy. Replacement anode rods can be purchased at local home improvement stores and are relatively easy to install.

You should replace your anode rod every 3 to 5 years. This can be done during your annual maintenance of draining and flushing the water heater. You may want to replace a low-quality anode rod with a better quality one that will last longer.

Signs You Need to Replace Your Water Heater

Age of the Water Heater

Age is a big factor in your water heaters performance. If your water heater is 10 years old or older you should expect to have higher maintenance costs or to replace it at any time.

If you’ve properly maintained your water heater, you may get up to 12-15 years of life from a gas water heater and 15-20 years form electric water heaters. Beyond that, replacement is recommended especially due to rapid advances in safety and energy efficiency. 

Another factor with age, particularly with gas tank water heaters, is the overall energy efficiency of the water heater. Energy consumption is higher in older water heaters versus newer models which will pay for itself over time. 

Rusty Water From Tank

If you are seeing rusty water or reddish-brown water from your hot water heater that’s an indication that rust is mixing with water inside your tank. It’s a clear indication that your water heater is in need of replacement. 

If the water heater is not leaking, you may be able to buy some time by performing a drain and flush maintenance on the water heater to remove loose sediment and change your anode rod. However, depending on the condition of the interior of the tank this service may not be sufficient.

Ultimately, if the tank is damaged or starting to leak there is no other option but replacement.

 Gurgling Sounds Inside Your Water Heater

As your water heater gets older sediment begins to build up at the bottom of the tank. When the sediment is heated and reheated over time it begins to harden.

If you hear banging, crackling or gurgling sounds from inside your water heater that is an indication that there is a sediment buildup inside the tank. It is recommended that you try to flush and drain your water heater. This maintenance may prolong the water heaters’ life if caught early. 

Depending on the amount of sediment build-up inside the water heater, the drain valve may be clogged or blocked preventing it from draining water properly. One option would be to try replacing the drain valve to clear sediment from the water heater. 

If all attempts to drain and remove the sediment fails, then replacement is the best option. In this case replacement of the water heater is recommended before a catastrophic leak occurs which could cost thousands of dollars of damage to your house. 

Leaking from the Bottom of a Water Heater Tank

water heater

If your water heater is leaking that is a good indication that there is something wrong. See our How to Repair a Leaking Water Heater – Complete Step by Step Guide for steps to repair a leaking water heater. You need to contact a licensed plumber to have them examine your water heater for repair or replacement. 

Some leaks can be repaired while others can not. If the leak is located around the top of the water heater such as around the supply pipe fittings or the T&P valve, repair may be an option. However, this is not always the case and is still an indication that there is something going wrong internally that needs to be addressed.

If you’ve noticed water on the floor around your water heater then you could have a serious problem. Internal leaks in tanks can’t be repaired. If water is leaking from the bottom of your tank you should plan on an immediate replacement and call a licensed plumber.

The Water Heater Stops Producing Hot Water

Hot water is a daily luxury we’ve all become accustomed too. No hot water can be a huge inconvenience. If your water heater is not producing hot water there are a couple of things that could be the cause. One is there is likely a problem with the heating element or the electric thermostat.

Another possibility is a broken drip tube. The drip tube is a plastic pipe that runs from the cold water inlet to the bottom of the tank. If this pipe is broken, cold water and hot water mix together resulting in lukewarm water from the tank.

These items do commonly fail over time and can be repaired by a licensed plumber. These items are fairly easy to replace for the handy do it yourself person. 

Cost to Repair a Tank Water Heater

If caught in time, most water heater repairs are fairly inexpensive and easy to do. However, this may not always be the best option. Here are some things that you should consider:

  1. How much the repair will cost? One of the things you should consider is the cost of the repair and whether you can do that repair yourself or if you need to hire a licensed plumber. If the water heater is it experiencing a higher level of maintenance, a replacement water heater will be your best option. 
  2. What is the life expectancy of the water heater? There’s no point in throwing good money after bad. If the cost of your repair is going to be as much is half the cost of a new water heater and will only provide a small amount of remaining life expectancy, then replacement would be your best option. 
  3. What is the cost of a new water heater? The last thing to consider is how much it will cost to have a new water heater installed by a licensed plumber. 

Cost to Replace a Tank Water Heater

Now that you’ve determined it’s time to replace your water heater, there are some things you need to consider:

  1. Will you be replacing the water heater with a similarly sized unit? When you decided that it’s time to replace your water heater it may be a good time to make an upgrade or to switch to a tankless system. Some of the factors that go into this decision will depend on your situation. Factors such as if you’re having to replace damage to your house caused by a leak or if you need to move the water heater to a new location.
  2. Do you need a larger tank to meet your family’s needs? If your family has grown since the last time the water heater was installed, a larger water heater may be desired. However, there are limitations to size when choosing water heaters depending on where you live.
  3. Will you install the water heater yourself or hire a licensed plumber? It is always recommended that you hire a licensed plumber to install a new water heater. Licensed plumbers in your area will have knowledge of local building codes that you may not be aware of. However, depending on your skill level you may be able to install your new water heater yourself. 

Be Aware of Hidden Costs

We touched on building codes and number three in the previous section. When you replace a water heater you will be required to meet all current building codes. 

There may be costs greater than just the water heater itself. Some of the hidden costs you may see when installing a new water heater include:

  1. Expansion tanks – expansion tanks are used to help control pressure inside and water heater. 
  2. Seismic strapping – depending on where you live seismic strapping may be needed if you live in an area prone to earthquakes.
  3. Drain pans – drain pans are placed under the water heater to catch leaks and discharge water to the exterior in order to protect the structure of your home. 
  4. Plumbing pipe upgrades – Depending on the type of plumbing supply pipes you have in your house upgrades may be needed. For example, if your home has polybutylene piping you will likely need to replace all accessible piping during installation.

New Water Heater Tank and Installation Costs

According to HomeDepot.com, the average cost of a new water heater installation is approximately $1,308. Nationwide costs typically range from $952 to $2,098. This replacement estimate includes the following components: 

  • Basic tank water heater – typical water heater size is 40 or 50 gallons.
  • Permits to install new water (some locations do not require this).
  • Installation materials such as fittings, shut off valves, piping, etc.
  • Installation labor by a local, licensed and insured plumber.
  • Removal of the old unit in accordance with local laws.

If you choose to purchase and install a water heater yourself, you can expect to pay between $350 to $2000 depending on the size and type of water heater you decide to purchase.

HomeInspectionInsider.com is owned and operated by Hubert Miles is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com. HomeInspectionInsider.com also participates in affiliate programs with other affiliate sites. Hubert Miles is compensated for referring traffic and business to these companies.

Hubert Miles

I've been conducting home inspections for 17 years. I'm a licensed Home Inspector, Certified Master Inspector (CMI), and FHA 203k Consultant. I started HomeInspectionInsider.com to help people better understand the home inspection process and answer questions about homeownership and home maintenance.

Recent Content