Plumbing, Water Heaters

What Is The Longest-Lasting Water Heater?

Longest Lasting Water Heater Lg

Water heaters have been a part of almost every American’s everyday life. But sometimes, water heaters have to end their service because of damages or simply being used for so long. So how long should a water heater actually last, and what is the longest-lasting water heater brand? 

Rheem water heaters are some of the best and longest-lasting water heaters on the market. The Rheem Marathon water heater has a lifetime warranty. Many other very notable brands like Bradford White, A.O. Smith, EcoSmart, and others are also excellent. Water heaters generally last 8 to 12 years, but a good one can last 20+ years with proper maintenance.

A water heater, just like any other appliance in your home, has a limited service life. However, the longer the heater’s lifespan, the lower the maintenance cost, the higher the efficiency, and the better the quality. 

Aside from Rheem, you have other water heater options to choose from when it comes to longevity. Here, we explore the longest-lasting water heater brands you should consider buying.

What Is the Most Reliable Water Heater Brand?

There is no denying that a long-lasting water heater is reliable. It’s likely to offer effective service any time you need hot water. 

However, with the high number of water heaters on the market, it becomes difficult to determine the most reliable products. Below, we highlight some of the most reliable heater brands worth your attention:

Rheem Water Heater

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Rheem is among the most reputable and reliable water heater brands in the industry. The company started manufacturing water heaters way back in 1925. 

Rheem has been reputable for developing quality water heaters for over 100 years. The goal of this company is to help families access the ultimate comfort in their homes. 

The company has an extensive range of water heater distribution producing gas, electric, solar, tank, and tankless products. However, it has invested a lot of resources in the production of tankless water heaters. 

Among tank models, the Marathon water heater is top-rated and comes with a lifetime warranty. It features include:

The Marathon water heater lifespan comes from two primary features:

  • they do not have an anode rod
  • they are made from modern materials that are resistant to corrosive properties within tap water.

You can read more about Marathon in our article Are Marathon Water Heaters Worth It? (Explained).

A tankless water heater from Rheem can recover quickly and requires little maintenance. Rheem has invested in research and technology to improve the quality of its products. 

Bradford White Water Heater

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If you’re after an all-American company for your hot water needs, there is no better company than the Bradford White Corporation. The company is reputable for its tankless water heaters and its immense contribution to commercial applications. 

Bradford White is known for developing a variety of products, with almost all of them being highly durable. They mainly produce electric and gas models. 

The price of the Bradford White water heater is higher compared to other products. However, they might be worth it in the long run. 

The best thing is that you’ll receive professional customer support any time you run into a problem while using a Bradford heater. You also stand a chance of accessing a 10-year warranty. 

Bradford White water heaters have received positive reviews from many customers who have used the products. 

A.O. Smith Water Heaters

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A.O. Smith is among the most popular and reputable water heater manufacturers in the United States and worldwide. The company is known for providing energy-efficient water heaters and other residential appliances. 

The company was started in 1874, and since then, it has maintained its high reputation in the industry. For this reason, it’s among the most trusted water heater brands. 

The company has also invested in research and technology to produce quality products all the time. Most of the water heaters from the company are 2.5 gallons. You can also get larger ones with a tank capacity of 120-gallons. 

All the products from A.O. Smith are durable, highly efficient, and effective. 

Rinnai Water Heater

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Rinnai is among the top water heater brands when it comes to efficiency and technology. The company was founded in 1920 is one of the largest Japanese water heater manufacturing companies. 

However, the company sells its products worldwide, and surveys show that over 32 million water heater consumers globally prefer products from Rinnai. 

The heater stands out from the rest thanks to its high performance and energy efficiency. Installing these water heaters is very straightforward. The heaters are also designed with care and with safety features to protect consumers. 

Rinnai products come with an affordable range, thanks to the support and engineering from the company. You’ll also like the fact that it comes with a 12-year warranty. 

EcoSmart Tankless Water Heater

If you’re seeking a water heater with an affordable budget, the EcoSmart water heaters are the best option for you. EcoSmart has been the most reliable independent water heater manufacturer, thanks to its green energy technology. 

The company’s signature products are the EcoSmart electric tankless water heaters. Many people like these heaters, thanks to their renewed technology that can increase performance by 45%. This will allow you to get more power with less energy consumed. 

The EcoSmart water heaters also come with smart boost technology. This technology is known to increase the efficiency of tankless water heaters. 

Water heaters from EcoSmart will offer you instant hot water any time you need it. The heaters are also both easy and cheap to install. 

Can Water Heaters Last 20 Years?

Yes, a water heater can last for 20 years. However, you should buy the most durable brand for it to last for that long. For instance, tankless water heaters can last for longer than tank water heater models. 

You should also do regular maintenance and repair if you want your water heater to last 20 years. Below are three things you can do to make your water heater last 20 years or more:

1. Flush The Water Heater Tank Each Year

Almost every water heater manufacturer recommends that you flush the water heater tank each year. However, draining it alone doesn’t flush the water heater. 

Here, you should check the manufacturer’s guide for the right procedure to drain water from your water heater. For instance, if you have a Bradford White water heater, follow the instructions below:

  1. Turn off the gas valve on the gas water heater. For the case of an electric water heater, turn off the electricity supply to the heater. 
  1. Shut off the cold water supply to your water heater.
  1. Open your hot water faucet. 
  1. Connect a hosepipe to the drain valve on your water heater and run it to the drain. 
  1. Open the drain valve and let your tank drain fully. 
  1. Turn on the cold water supply to your water heater. 
  1. Let the water go through the heater and out of your drain valve. Do this for about 5 to 10 minutes. 
  1. Close your drain valve and let the tank refill. At the same time, keep your hot water faucet open. The tank is full when you note water coming out of the faucet. 

2. Replace the Anode Rod If It’s Corroded

Manufacturers put the anode rod in the water heater tanks to prevent the inside of the tank from rusting. You must check the anode rod annually each time you drain the tank. 

Always remember that replacing a corroded anode rod is cheaper than replacing the whole heater. A bad anode rod will cause hot water to rapidly corrode the tank’s inside, thus shortening its life. 

3. Insulate Your Hot Water Tank

Insulating your water heater is a one-time job that has enormous benefits in the long run. Insulating your water heater tank can increase its efficiency by at least 40%. 

Energy efficiency can translate into a good saving on your utility bills. 

What Is The Lifespan of a Water Heater?

It’s a fact that all water heaters are created to last for over ten years, whether tankless or tank water heaters. However, the exact time the heater will last depends on how you maintain it. 

You should therefore be keen to identify common challenges and correct them when they occur. 

The Lifespan of Tank Water Heaters

Most tank water heaters last for 8 to 12 years on average. However, when these water heaters are maintained and used appropriately, they can even last for more than 15 years. 

The tank is designed with an anode rod to attract corrosive elements in water, thus protecting the inner linings from rusting. This prolongs the durability of the tank. 

If you wish to lengthen the life of a tank water heater, you should check the anode rod each year. 

The Lifespan of Tankless Water Heaters

Tankless water heaters are designed with advanced and complex technology that makes them long-lasting compared to tank water heaters. For this reason, the heaters have a lifespan of 20 years. 

However, with proper maintenance, a tankless water heater can last for more than 30 years. Tankless water heaters are referred to as “on-demand water heaters” thanks to their ability to heat water instantly. 

They only function when you require hot water, thus increasing their lifespan. They also corrode at a slower rate than tank water heaters

Factors That Affect the Lifespan of a Water Heater

Several factors are affecting the lifespan of a water heater, as we’ve highlighted below:

Quality of Water

If your heater is heating hard water most of the time, its lifespan is likely reduced by about two years. Hard water has minerals that reduce the efficiency of the heater. 

You can apply softeners to remove minerals before they get to your appliances. 

Maintenance Practices

If you don’t do maintenance and repairs regularly, your heater might get damaged after a few years. However, a well-maintained water heater can last longer than you would expect. 

The Materials of the Heater

If a water heater is developed from a high-end material such as fiberglass, it’s likely to last longer compared to those made from steel. 

Source of Power

Depending on the manufacturer’s specification, a water heater can either use natural gas or electricity. Electric-powered heaters have proven to be more durable than gas-powered heaters by at least 1 to 2 years. 

Location of Installation

If you install the heater in a cold crawl space, it’ll struggle to maintain the desired water temperature. The heater will wear out quickly and even end up breaking down. 

Installing your heater in a temperature-controlled home will ensure that it lasts longer.

How to Determine the Age of a Water Heater

Now that we have estimated the lifespan of a water heater, we can determine the years you need to replace it. However, this is only possible when you know the heater’s age. 

There are cases when you buy a used heater but don’t know its age. If it’s the case, how would you estimate the heater’s age? 

In such a situation, check the water heater’s serial number. The letters on your heater and the first two numbers represent the month and year the heater was manufactured. 

The letters are from A (January) to L (December). You can contact your manufacturer to help you out in case you’re finding difficulties. 

When To Replace Your Water Heater

Most heaters will start showing signs of breakdown when they hit the age of 10 years. However, some heaters might fail a few years after you buy them.

Your heater might fail due to the following reasons:

  • Sediment Buildup: As your water heater heats water continuously, contaminants might lead to sediments forming at the surface of your tank and harden over time. This will accelerate damage to your water heater and reduce its efficiency. 
  • Over Pressurization: This happens when the water pressure in the tank exceeds its limit. This will force the heater to fail. Over-pressurization in your tank could result from excessive heating. 

When you notice any of the signs below, make arrangements to purchase a new water heater:

Rumbling Noises

As the heater ages with time, you might begin hearing some strange noises coming from the product as it heats the water. The noises may become louder when you use a lot of hot water in your home. 

This is mainly due to sediments building at the bottom of your water tank. The situation is worse if you live in Arizona and don’t have any water softener. 

I recommend that you flush water at least each year to reduce the buildup of sediments at the bottom of your tank. 

Buildup of Rust

If your heater starts to rust, it is enough to tell you that it’s almost breaking down. Even though most heaters are designed from stainless steel, they can still rust in the long term. The rust might start slowly and reach a point where the heater becomes fully insufficient. 

You’ll start noticing corrosion or rust around the water inlet connection, water outlet connection, and pressure relief valve. Unfortunately, replacement is the only option you have for a water heater that has started to corrode or rust. 

Leaking Hot Water Tank

When your water heater starts to leak, it’s enough reason to replace it. Water heaters start to leak when they start to corrode and rust from the inside. If you don’t control the problem, it might lead to bodily harm or the destruction of your property. 

To avoid leaks, go for the tankless water heaters. You can also install a leak detector under the heater tank to alert you when a leak happens. Thankfully, there are various water sensor alarms for such functions. 

Supplying Lukewarm or Cold Water

If either lukewarm or cold water starts coming out of your faucet instead of hot water, there is a need to replace the heater. This might be due to a broken heating element. 

You can always repair the heater’s thermostat or heating element when they break down. If the heater produces cold water because your home’s demand exceeds its size restrictions, you’ll have to replace it with a larger heater. 

Replacing a Water Heater

If your heater shows signs of breaking down, it might be time to purchase a new one. However, if it is just a few days old and the warranty is still in effect, you can contact your manufacturer to look at it before you buy a new one. 

After you have purchased a new heater, you can either install it yourself or call a professional electrician or plumber to help you out. Most water heater dealers will send an expert to help you with the installation when you buy a water heater.


As we have seen, the lifespan of most water heaters is above ten years regardless of whether it’s a tankless or tank heater. However, the exact lifespan of the water heater depends on how you maintain it. 

A water heater can even last for over 20 years. This means going for the most durable water heater brands. Select from any of the water heater brands that we have recommended above. Remember that tankless water heaters last longer than the tank water heater models.  

If you notice your heater producing strange noises, rusting, or leaking, it would be the best time to replace it. Only replace it with an energy-saving model. 

You can do the replacement by yourself if you have the required skills. There is also the option of calling a professional plumber or electrician to help you with quality work. We hope that your water heater lasts for a longer period. 



Hubert Miles | Licensed Home Inspector, CMI, CPI

Hubert Miles is a licensed home inspector (RBI# 2556) with more than two decades of experience in inspection and construction. Since 2008, he has been serving South Carolina through his company, Patriot Home Inspections LLC. As a Certified Master Inspector, Hubert is dedicated to providing his expertise in home inspections, repairs, maintenance, and DIY projects.