How Long Do Water Heaters Last?

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How long do Water Heaters Last

When installing a water heater, you want it to last and serve you efficiently. It is therefore important to ask yourself how long do water heaters last before making the purchase. The lifespan of a water heater depends on various factors, including the type of heater, the location, and the quality of your water. This article will help you to answer the question – How Long do Water Heaters last?

There are two main types of water heaters available for purchase and use. The two types have varying lifespans. However, each type is efficient in its own way. The types are tank storage water heaters and tankless water heaters. 

These heaters work differently and this is why their lifespan also differs. The tankless water heaters heat water when needed and the tank water heaters heat water continuously. 

How long do Water Heaters Last?

Between 8 to 12 Years

The average Residential Hot Water Heater will last between 6 to 12 years. However, some may even last up to 15 years if properly maintained, and tankless water heaters can last up to 20 years.

Depending on your need for heated water, you can purchase any of the two types. It is important to research and ask how long the water heater will last. Buying your heater from a reliable source will give you a guaranteed warranty and peace of mind.

While using your water heater, you will need to understand the various factors that affect its lifespan and when it is time to have the heater replaced.

How long do Water Heaters last?

No matter the type, water heaters are all built to last for more than ten years. The important factor is how the user maintains the heater, as this is the main factor when it comes to the heater’s lifespan. 

When you notice that your water heater has an issue, you should handle it immediately to keep it operational and extend its lifespan. Let’s review the lifespan of each of the water heater types. 

How Long Do Water Heaters Last

How long do tank water heaters last? 

These types of water heaters have a lifespan of approximately 8 to 12 years. The heaters can, however, last as long as 15 or more years if well maintained. The heaters have a tank with a rod that collects harmful elements in the water and this protects the heater’s interior lining from getting corroded.

When a tank water heater is used for about ten years, this rod gets consumed by the corrosive particles and it can no longer function as it should. This lets the harmful elements get to the interior lining and bottom of the tank and damages it. 

When the tank gets destroyed, it might begin to leak. You, therefore, need to handle the tank leaking problem before it gets worse and leads to the heater’s malfunctioning.

How long do tankless water heaters last?

Tankless water heaters last longer than tank water heaters because they operate using advanced technology. These heaters can last for approximately 20 years although, with good maintenance, they last for as long as 30 years.

Tankless water heaters are very common and are preferred by many. This is mainly because they heat water only when needed and they are commonly referred to as on-demand water heaters. These heaters do not have to run continuously like tank water heaters to heat water. 

The tankless water heaters also corrode as they continue to operate. However, this happens slowly when compared to tank water heaters. This is important information that could guide you as you purchase your water heater.

Determining the lifespan of Water Heaters

When you already understand the estimated lifespan of each of the types of water heaters, you can easily tell when it is time to replace yours. It is important to know the age of a heater when determining its lifespan. 

In some cases, you may inherit a heater that you did not purchase yourself. This is usually the case when moving into a new house. 

So how do you determine how long the water heater will last? You need to know its age or how long it has been operating.

To determine the age of a water heater, check the serial number on the heater. This number will contain a letter and some numbers. On the serial number, the letters and starting two digits signify the month and year the heater was manufactured and they appear respectively.

The letters on the serial number can only be between A and L, representing the 12 months in a year.


If the serial number on the water heater is B100175620 for instance, B will be telling you that the heater was manufactured in February, which is the second month of the year. The first two digits ‘10’ signify the year 2010 as the year of manufacturing. 

How Long Do Water Heaters Last

Factors to consider in determining how long a water heater will last

In determining how long a water heater should last, you need to consider several factors. These are factors that may affect the lifespan of the heater in a good or bad way.

1. Power source

You can use natural gas or electricity to run your water heater. The source of power to use mainly depends on the manufacturer’s recommendations. Water heaters that use electricity have a longer lifespan compared to those that use gas. The gap in the lifespan is normally 1 to 2 years.

2. Water quality

Depending on the quality of water the heater has to heat, the lifespan may be affected. If the water is hard, the heater will likely last for a shorter period by approximately two years. 

This is because there are minerals found in hard water that clog onto the water heater making it less efficient. You can use water softeners to get rid of the hard water minerals before they get to your water heater.

3. Water heater material

Some of the materials used in making water heaters include fiberglass, which is high-end. Fiberglass lasts longer than materials such as steel. The material used in making a water heater, therefore, determines how long it will last.

4. Where the heater is installed

The location of a water heater installation will either help it to work for long or wear it out sooner. Cold and damp places make the water heater break down sooner as it has to strive to maintain the required operational temperature all the time. 

It is therefore advisable to have the heater installed in a space that has proper temperature regulation.

5. Water heater maintenance

Like all other appliances, water heaters need maintenance in the course of their lifespan. It is important to repair and maintain your water heater regularly to give it a longer lifespan.

How Long Do Water Heaters Last

When to have your water heater replaced

When you are using a water heater and you notice the following factors, then you know it’s time to replace your heater.


When your water heater starts rusting, it might be because it is about to break down. Stainless steel is a material used in making most water heaters. However, the heaters may end up rusting with time. 

Rust slowly corrodes the water tank and makes the heater inefficient. Rust mainly occurs on the valve that releases heater pressure on the water outlet connection or the water inlet connection. A rusting water heater is best replaced as it cannot be repaired.

Leaking hot water tank

A leaking hot water tank should be replaced. Internal corrosion in a tank causes a water heater tank to leak and this is dangerous. A leaking hot water tank may explode and cause a lot of harm or destroy some of your property. 

Work on a leaking hot water tank immediately you identify it. You can also avoid leakages by going for tankless water heaters. Another option is to have a leakage detector installed beneath your tank water heater to get an alert in case of a leakage. There are many alarms for water sensors available that you can buy.

Rumbling Noises

When your heater begins to give rumbling noises, it is probably aging out. The noises will be heard during water heating and this may become louder and noisier with time. The rumbling noises are mainly caused when elements build at the bottom of the tank. 

This will mainly occur if you use hard water without water softeners. If you live in an area where there is hard water, it is advisable to ensure that you flush your water heater annually to manage the buildup of the sediments at the tank’s bottom. This flushing will give your water heater a longer lifespan.

Lukewarm or cold water

When your heater starts giving you cold water, it is a sign that it should be replaced. A heater will start providing cold or lukewarm water for reasons such as a heating element that is broken. 

You can simply opt to replace a heating element and the heater’s thermostat. Another reason why a heater may provide cold or lukewarm water is that the demand for hot water from the heater is more than the recommended size and water. If this is the case, you will have to replace the heater with a bigger one to meet your higher demand.

10 or more years of operation

If your water heater has been in use for more than 10 years, it begins to wear out. It is, however, not a guarantee that all water heaters purchased will remain in operation for 10 years since some break down earlier. 

The 10 years lifespan may cause your water heater to wear out because of elements building-up on the heater with time. For the tank water heaters, the more the heating and reheating of water occurs throughout, sediments form at the bottom of the tank with time and they even harden. This damages the tank and it may fail to operate as it should.

Another reason for water heaters to fail to function efficiently after 10 years is over-pressurization. This is when water in a tank water heater exceeds the pressure limit. The excess pressure pushes the heater to break down and this can mainly be caused by too much heating in the tank.

How Long Do Water Heaters Last

Replacing a water heater

When you identify some of the above issues with your water heater, you can choose to have it replaced or repaired. In some cases, the heater may begin to give you problems before the warranty expires. 

You should reach out to the manufacturer to check the water heater before you move ahead and replace it. If the issue with your heater demands that you buy a new one, proceed to do so as an old or damaged heater is inefficient. You can replace a water heater on your own or get a professional to help you out.

You can get an electrician with experience installing heaters or a plumber” target=”_blank” rel=”noreferrer noopener sponsored”>professional plumber. It is also very important to purchase a water heater from a reliable source as there are many counterfeit products. 

You will need to keep checking your water heater to know if it has any issues that you need to address. You do not have to wait until a small issue with the heater becomes too much as it may be very dangerous for you. Also buy a heater that helps you to save on energy and heating costs, therefore, saving you money.

How much does replacing a water heater cost?

It will cost you anywhere from $400 to $8000 to buy a new standard tank heater. A tankless heater, on the other hand, costs approximately $250 to $2,500. The prices may vary depending on where you are purchasing your heater from.

Can a water heater last 20 years?

With proper maintenance, a water heater lifespan can be up to 20 years. Maintaining a water heater that long entails replacing parts of the heater when necessary and having it flushed often. While very few water heaters last that long, it is possible.

A water heater is important in our homes and a heater with a good lifespan is not only efficient but will help you to save money.

The H2Home Lab team is dedicated to helping you find the best solutions to your specific water needs, as well as provide troubleshooting tips and guides for water filtration, heating, softening and plumbing. We hope you will find the info you need on our site from any one of our buying guides or subject matter articles.

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