Updated January 22, 2024

If your old water heater needs to be replaced, upgrading to a tankless water heater can be a fantastic choice. Although they do require a larger upfront investment, tankless water heaters have many advantages over traditional tank-style units. One of the biggest advantages is that tankless units typically have a far greater life expectancy than any other type of water heater. Here is a full overview of how long tankless water heaters should last, how they work, and why they’re such a great choice.

Typical Lifespan for Tankless Water Heaters

A tank water heater will usually last for somewhere between eight and 15 years at the very most, depending on whether the unit is gas or electric. Gas units generally have the shortest lifespan, as they tend to have more issues with the tank corroding and beginning to leak.

No matter whether you opt for a gas or electric tankless water heater, it is almost certain to last for years longer than any other unit. On average, a new tankless water heater should last for a minimum of 20 years, and it is not uncommon to find units that still function effectively for 25 to even 30 years or more.

As with any other appliance, there is obviously a chance that your tankless water heater could fail prematurely. However, the risk is still smaller since tankless units have fewer components, so there are fewer things that could malfunction.

Another advantage is that tankless water heaters tend to have better warranties than tank units. A new gas or electric tank water heater will typically only be under warranty for five years, and this warranty may not cover all of the unit’s components. Most tankless units, on the other hand, will have a 10-year warranty on the unit’s heat exchanger and up to a five-year warranty on all the other components.

How Maintenance Helps to Protect a Water Heater’s Lifespan

Another advantage of tankless water heaters is that they tend to be lower maintenance than tank units. It is still a good idea to have your tankless unit inspected by a plumber every year or so to ensure it doesn’t have any issues that could lead to increased energy usage, decreased effectiveness, or potentially lead to the unit breaking down. Nonetheless, you still won’t have near the number of maintenance tasks with a tankless unit.

The main thing you need to do is have the unit flushed and cleaned every year or two. However, you may want to have the unit cleaned every six to nine months if your home has hard water. Flushing and cleaning are important for preventing mineral deposits and limescale from building up on the heat exchanger and other components.

All tankless water heaters use a heat exchanger that is similar to that used by a furnace. The metal heat exchanger absorbs heat from either the gas burner or the electric resistance coil and becomes extremely hot in just a few seconds. Cold water then flows over the metal exchanger, and the heat energy is transferred to the water to instantly make it hot.

Even if your home has fairly soft water, it will still contain some dissolved minerals. As water flows through the unit, some of these minerals will be left behind and form a hard scale that can start to coat the heat exchanger. This can eventually lead to issues with the unit not heating properly, as the mineral deposits will insulate the heat exchanger and prevent the water from coming into direct contact with the metal.

As a result, much less heat will be transferred to the water, which means the water won’t heat as quickly, and the unit will use more energy. While this may not sound like that big of a deal, limescale deposits can potentially increase the amount of energy the unit uses by 30% or more.

Regular cleaning is important because it prevents limescale build-up while ensuring the unit continues functioning effectively and efficiently. If you neglect to have the unit cleaned and descaled, the limescale can build up to the point where your only real option is replacing the heat exchanger. Unfortunately, this generally isn’t something that would be covered under warranty since the problem isn’t related to a defect but instead due to neglect or lack of maintenance.

Why Tankless Water Heaters Are Such a Great Choice

In addition to having a longer lifespan and fewer maintenance requirements, tankless water heaters also have several other advantages over tank units. One important thing to consider is that tankless units are much more energy efficient, and the increased energy savings can go a long way toward offsetting the higher initial cost.

Exactly how much you can save with a tankless unit primarily depends on your average hot water usage. The savings will always be greatest if you use less than 40 gallons of hot water on average daily. In this case, a tankless water heater could cut your energy costs by 40% or more. Even if you typically use more than 80 gallons per day, you should still save 10% or more on energy costs compared to using a tank water heater.

Of course, this also depends on whether you opt for a gas or electric tankless unit. Electric units will always be a bit more efficient. However, they are also a bit more expensive to operate since natural gas is usually cheaper than electricity.

Another great thing about tankless units is that you won’t have to worry as much about the unit suddenly having a major leak and flooding the surrounding area. This isn’t to say that a tankless unit can’t leak, as there is always the potential for leaking with any plumbing fixture. Nonetheless, you still don’t have to worry about a tankless unit failing and sending tens of gallons of water rushing out as you do with tank units.

The fact that tankless water heaters don’t store water also means that you can basically use as much hot water as you want without worrying about running out. With a tank unit, you could easily run out of hot water after only two or three showers, in which case you may need to wait for anywhere from 30 minutes to two hours before your water gets hot again.

Expert Plumbing and Home Services

If you’re looking to upgrade your home with a high-efficiency tankless water heater or your current water heater needs to be serviced or repaired, Golden Rule is here to help. We install and service both tankless and tank units, and we also offer professional drain cleaning, leak repair, and a full range of other residential plumbing services. We pride ourselves on reliability, and more than 99% of all calls we receive are serviced that same day. Our company has been serving customers in Grimes and the Des Moines metro area for more than 20 years, and we are ready to take care of any of your plumbing, electrical, or HVAC needs. For more information on the advantages a tankless water heater can provide for your home, give us a call today.

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