How Long Do Tankless Water Heaters Last?

tankless water heater life

To avoid unexpected and often unpleasant doses of cold water, you have to keep accurate tabs on the water heater. Of particular importance is the fact that you should know how to estimate the outflow rate of the water from the tank. Our goal in these discussions is to let you know how to do just that.

How Long Do Tankless Water Heaters Last?

Before we can delve into showcasing just how long a tankless water heater lasts, we shall look into the factors that determine this length. The following are some of the factors that contribute to the longevity and overall lifespan of the tanks:

tankless water heater life

Water Quality

The quality of water is by far the single most significant determinant of the longevity of the water tank. Muddy, brackish, or salty waters tend to deteriorate the tanks much faster than the pure waters. That is because of the high levels of impurities that dissolve in the water.

They tend to wear out the structural components of the tanks in such a way as to pose some damages thereof. Moreover, they also impose higher levels of electrical energy consumption.

Frequency of Usage

How often you use the water tanks also has a bearing on the longevity thereof. A tank that is used every now and then will definitely deteriorate much faster than that which is used only once in a while.

If you are keen on making good use of a tank for a prolonged duration of time, you should consider using your moderately. That way, you will pose limited damages to the structures and guarantee long-term use.

Maintenance and Cleanliness

Other than moderate use, regular cleanliness and maintenance of the tank is also another sure way of lengthening the lifespan of the water tank. By cleaning it on a regular basis, you get to eliminate all impurities and up the performance.

With reduced impurities also comes the reduced incidences of corrosion which in turn reduces the pace of deterioration. It hence goes that the tanks that are washed often last longer and vice versa.

Structural Makeup

The kinds of materials that are used to make the tank up also contribute to the longevity thereof. Those that are made of tough materials like stainless steel and Aluminum tend to last longer as they endure the test of time better.

On the flip side, those that are manufactured using plastics or variations thereof tend to last a shorter duration of time. It is in your best interest to find that one which is more likely to endure the test of time.

Climate and Weather Patterns

Some weather patterns have been noted to impact adversely on the longevity of the water heaters. Climates that tend to vary widely are the chief contributors to the faster aging of these appliances.

That is because when substances expand and contract spontaneously, they tend to develop cracks and leakages. If and when these widen unabated, they tend to wear out the structures in such a way as to make them become too obsolete too soon.

Year of Manufacture/Serial Number

Lastly, the year the water heater was manufactured also comes in handy. This is captured in the serial number which is displayed on the product. A typical serial number comprises a letter that is followed by several numerals.

The letter denotes the month of manufacture. For instance ‘A’ for January, ‘B’ for February and ‘C’ for March and so on. The numerals that follow on the other hand denote the year of manufacture. BY skimming the serial number, you will be able to know when the tank was manufactured and when it will likely become obsolete.


When all factors are put into consideration, expect a brand new and original tankless water heater to take you for around 20 years. This length may extend to 25-30 years if the broken parts and components are replaced from time to time.

The lifespan we have denoted stands in sharp contrast with the storage tank which manages a paltry 10-15 years. There you have the information you need to keep your tanks in the proper functioning states. Haven’t you? Go ahead and make maximum use of yours for the better!



David: Penn State-educated Mechanical Engineer and Business-savvy Fluid Dynamics Specialist. Balances family plumbing business support with a thriving engineering career at a top, undisclosed company. (they want it that way) I help Will with plumbing and HVAC needs on his Real Estate.

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