How Long Does A Water Heater Last? (You’ll Be Surprised!)

If you’re asking “how long does a water heater last?”, you’re probably wondering if your own hot water heater has reached the end of its life. If the answer was based just on the age of your unit, knowing whether to move on or stay put would be easy. But determining its lifespan is more complicated than determining its age.

What you don’t want to do is spend your hard-earned dollars on the premature purchase and installation of a brand new water heater before it’s time. So let’s first figure out together what should be the proper lifespan of your particular water heater.

How to Determine a Water Heater’s Lifespan

Because estimating how long a water heater lasts is difficult to determine, we need to understand a few things first. Here are the 6 most common variables that make a difference in the longevity of your heating unit:

  1. Age
  2. Type
  3. Quality
  4. Location
  5. Water
  6. Maintenance

1. Age of Water Heater

Generally speaking, you can expect anywhere from 8-20 years of life out of your water heater. That’s a pretty big range which doesn’t tell you a whole lot. But it’s a starting point. Your first job is to determine the age of your unit.

If you don’t remember the year it was installed or don’t have the purchase receipt handy, you’ll need to learn how to read the label. You would think that the year of manufacture would be placed right on the label but it’s not that easy. Instead, you need to decode the serial number for your water heater.

How long does a water heater last - labels for gas and electric models
Everything you need to know about a water heater is on its labels. However, knowing how to read and understand them is a different matter. Even a gas and electric model of the same water heater can have the information in different areas.

Here’s how to decode the serial number — to determine its age — for each of the three largest manufacturing brands in the country (keep in mind, each of these manufacturers make many other brands that we’ve noted below):

A.O. Smith Water Heaters

Here are the instructions for how to determine the year your unit was manufactured if you have one of the A.O. Smith brands:

Rheem Water Heaters

Here are the instructions for how to determine the year your unit was manufactured if you have one of the Rheem brands:

Bradford White Water Heaters

Here are the instructions for how to determine the year your unit was manufactured if you have one of the Bradford White brands:

2. Type of Water Heater

How long your unit lasts also depends its type or style. Here are some general lifespan averages for the most common and popular styles:

Each of the above have their own pros and cons. But if you’re just trying to figure out if you need to replace your water heater, then combine the age with the information in the tables above. Barring any other issues with your water heater, you’ll have good idea if it’s getting close enough to an expiration date to consider a replacement.

PRO TIP: Don’t forget to take into consideration your warranty’s length of coverage. For example, tank-style electric water heaters usually come with a standard six-year warranty. So, from 7 to 15 years of age, all the costs and maintenance will be on you.

3. Corro-Protec

Corro Protec is a powered anode rod manufacturer. The powered anode rod is able to replace the sacrificial anode rod, in just a few simple steps. There are many benefits to the anode rod that make it a worthwhile investment. 

Powered anode rods make a current that keeps the sulfur smelling bacteria at bay, it prevents lime scale build up and so much more. 

3. Quality of Installation

Obviously, a novice will have little idea if a water heater has been installed correctly. But if done incorrectly, it will lead to a shortened and costly lifespan. Here are some of the installation issues we see all the time. They cause plumbing emergencies and even health risks, not to mention possible explosions and water damage.

  1. TPR Valve (Temperature and Pressure Relief Valve). When the pressure inside your tank is too high, the TPR valve will release it. A blocked or improperly installed TPR is a potential explosion waiting to happen.
  2. Temperature Setting. Although easy to set up, setting the thermostat incorrectly is a common, careless mistake. Your temperature should be set between 120 and 140 degrees. Unlike an explosion, the damage here is over time. To save money on energy costs, prevent buildup (called scale), and increase lifespan, the setting needs to be from 120 to 140 degrees. It should never be higher than 140 and only set lower than 120 while on vacation.
  3. Gas Lines and Flues. This applies to gas units only. A poorly installed gas line can lead to an explosion. And an incorrectly installed flue will allow dangerous carbon monoxide and other fumes into your home.
  4. Size Matters. We see this one all the time due to bad installation practices. A unit that’s too small for your home will not provide enough hot water. If the water heater is too small, it will work too hard to try to keep up with your hot water demands. A unit too large will consume more energy than is needed to supply your home.
  5. Leaks. This is another common issue we see in poorly installed units. These leaks not only cost you money, but over time can cause lots of water damage. In addition, it makes the area around the water leak a perfect environment for bacteria and mold. If the water leaks onto the unit, it can corrode.
How long does a water heater last - installation of water heater
Proper installation of your water heater prevents costly maintenance issues (and water damage or health issues) while maximizing its lifespan.

4. Location of Your Water Heater

How long does a water heater last if placed in the wrong location? This might seem like a small thing. Perhaps it is. It’s not like placing it in a poor location will cause an explosion. On the other hand, every little bit helps.

Most water heaters are located in the basement. They are snug as a bug in a fairly well heater area. However, we often find them located in a less insulated area of the home, like a garage. Because most garages are not heated — some aren’t even insulated — the air is colder than in the rest of the home. This forces your unit to work harder to heat your water to the proper temperature.

PRO TIP: A poorly located hot water heater will increase your energy costs while draining its lifespan. Whether your unit is in a good or poor location, wrapping it in insulation can only help.

Before and after of insulated water heater
It’s always a great idea to insulate your water heater. This is especially true if it is located in a drafty or colder than normal area of your home, like the garage.

5. Type of Water Used in the Home

Believe it or not, the type of water coarsing through your pipes and water heater can affect its life. Most homes get their water from a local municipality. The vast majority of this water is considered “hard.” This means their are hard minerals in the water which can cause buildup of scale (a type of corrosion) which over time causes damage.

Is there anything you can do about this? It depends on your budget. The best way to solve this problem is to convert your hard water into soft water using a whole-house water softener. You can learn more about the benefits of a water filtration system here.

Hard water damages to household fixtures
Hard water cause scaling, which you can see here on these common household items. Scaling in your water heater will also be prevented with the use of a whole-house water softener system.

6. Regular Maintenance Increases Longevity

This is probably our most obvious recommendation and it does seem a bit self-serving. But regularly scheduled maintenance is the best thing you can do to prevent problems and increase the life of your water heater. Here’s what water heater maintenance includes:

A typical water heater inspection includes all of the connected pipes; the removal of any debris or dust buildup in and around the unit, including a new filter; flushing out of the system; and checking all valves and the thermostat, including temperature settings. Maintenance should also include checking and cleaning of your ignition system and any fuel-related heating elements.

PRO TIP: Typically, for a nominal annual fee, HVAC installers will sell you a plan that allows them to keep your water heater in top working condition. It will also catch problems before they become disasters. In fact, upon installing our new unit, we contracted with our provider. After just three years it has caught a few problems early, saving us tons of money already.

A trusted plumber can also help you with any repairs or proper installation. In either case, you’ll maximize the life of your unit, keeping you from paying the big bucks sooner than necessary.


It’s worth checking the age of your water heater before you install a new one. Knowing (1) generally how long your particular water heater should last, (2) its date of manufacture, and (3) the variables that shorten or lengthen its life, will give you the answer you need.

This kind of knowledge will keep you prepared before your water heater gives up or fails, which can be inconvenient at best or cause catastrophic water damage at worst.

Call 1-Tom-Plumber for More Help

Don’t hesitate to contact us here or call us at 1-Tom-Plumber (1-866-758-6237) if you’d like help with your water heater. We will immediately handle any emergency plumbingdrain, and water damage problem, including excavation of underground water lines and sewer main lines.

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