How Long Does a Water Heater Last, Exactly?

Oct 29, 2022

How Long Does a Water Heater Last, Exactly?

What is the Life Span of Water Heater?

It’s freezing outside, but you need to get ready for the day. You’re in the shower, about to welcome the flow of warm water in your body when you get hit by cold water instead. You turn off the shower and turn it on again; still, cold water rushes in. What should you do? You run to your heater and realize that it’s not working at all! So, you get dressed, head off for the day without a shower and perhaps, a bad mood.

Getting into a cold shower during the freezing months is one of the worst things that can happen to you. That is why you need to know essential information about your heater. Besides learning how it works and maintaining it, you should also be aware of how long it’s supposed to last.

There are times when your water heater has been around for too long, and repairs won’t cut it anymore. In this case, a replacement is the best course of action.

But first, how long does a water heater really last?

Traditional Tank-Type Water Heater

If you have a traditional tank-type water heater, it can last an average of 8-12 years. An anode rod protects the interior lining of the tank, which you can find inside it. If the rod has corroded to the point that it can no longer do its job, corrosive particles will settle at the bottom of the tank and eventually destroy its lining. When this happens, it’s a strong indicator that the water heater has entered its final stages of life.

Tankless Water Heater

Tankless water heaters, also known as on-demand water heaters, can last up to 20 years. Sometimes, they can last longer than that. Since tankless water heaters don’t work continuously to maintain a supply of hot water, they last longer than their tank-style counterparts.

Tankless water heaters don’t use anode rods, but they can also suffer from corrosion and require replacement.

Several factors can affect your water heater’s life, such as:

  • Water quality: Did you know that hard water can damage your water heater? Besides that, hard water can even reduce the service life by two or more years.
  • Water heater location: Water heaters in crawl spaces or garages are a big no-no. These areas experience significant temperature drops that will force your water heater to work harder to heat the water. In turn, it will wear out the heater quickly compared to units installed in temperature-controlled areas.

A Way to Know the Water Heater’s Age

Say you have moved into a new house and the previous owner told you that the heater’s about x years old. Naturally, you want to prove this; therefore, you need to find evidence that the heater is x years old. So, how do you do this?

If there’s no documentation for the appliance, you can see it in the serial number. The serial number consists of a letter followed by a series of numerals that you can find on the water heater’s upper portion to determine its manufacturing date.

Usually, the letter stands for the month. For example, “A” is for January and so on. The next two numbers indicate the year it was made. So, if it leads with “A10,” it was manufactured in January 2010.

Typically, this applies to most hot water heater manufacturers. If you still want a more solid confirmation, you can confirm this on the company’s website.

What to Look Out For

During the water heater’s second half of life, you will notice signs that a replacement is coming soon. Here are some signs to watch out for that means you should start shopping for a water heater replacement before you get hit unexpectedly by a dose of cold water in the shower again:

  • Noises in the heater: If you hear strange noises coming from the heater, such as banging or rumbling noises, that only means your water heater is nearing the end of its lifespan. The noises are due to the calcium buildup from hard water that accumulated in the bottom of the tank, which forms into sediment that hardens. Eventually, this forms a thick crust that can cause the water heater to produce strange noises.
  • Water discolouration: If you notice discoloured water with tints of red or the water looks a dirty yellow, this could mean that there’s rust. However, observe it first. If the discolouration appears when cold water isn’t running, then the problem may be coming inside the water heater.
  • Pools of water: If you notice pools of water around the base of your water heater tank, then you’re in for some bad news. But first, identify where the leak is coming. In some cases, the leak may be coming from a fitting or valve that only needs to be tightened or replaced. It’s best to have a professional check this first. In the case that the leak is coming from the tank itself, it may be because of internal cracks or corrosion.

Prepare for Water Heater Replacement

Your water heater isn’t meant to last forever. So, when you know its predicted lifespan, it’s ideal to start thinking about replacement two years before you reach the end of its predicted lifespan.

By doing so, you avoid breakage and the inconvenience of not having hot water. Moreover, this will also help you minimize energy consumption.

Keep in mind that water heaters, after several years of use, are subject to mineral deposits and sediment buildup, which will force them to work harder to produce more power. When this happens, it will affect the appliance’s efficiency.


When you know your water heater’s predicted lifespan, you will be able to prepare for a replacement years before it reaches its end. That is also why you need to know this information to help prevent inconveniences and hassles along the way. Surely, you don’t want to get stuck with only cold water when it’s freezing outside, right? When it’s time for a replacement, work only with trusted HVAC professionals to tackle the job.

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