Stiebel Eltron Vs Ariston

We cannot imagine our lives without having warm water in our homes. When it comes to choosing new water heaters, it can be challenging to pick the right one. So, which is a better brand – Stiebel Eltron vs Rheem?

Electric water heaters have been rather popular units in the latest years. They are simple, energy-efficient, and somewhat affordable to install. All of this is why many homeowners prefer them over gas or solar ones. Also, many brands opted to manufacture various types of electric heaters.

Stiebel Eltron and Ariston are two well-known brands that most people who’ve looked for water heaters at least once have heard of. But which one should you opt for?

Stiebel Eltron Vs Ariston Comparison


Both brands are well-known and reputable, and they make exceptional products.

  • Stiebel Eltron has been around for almost a century, and they rarely leave their customers dissatisfied. They are among the world’s leading suppliers of green tech products, and among them are electric water heaters.
  • Ariston Group, while about a decade younger, doesn’t fall behind Stiebel Eltron regarding quality and reputation. They are among the leading manufacturers of water heaters, producing various heating systems and other units.

As you can see, both brands are reputable, and comparing these two might seem like a daunting task. Still, if you look into all of their products, you can see a pattern that might help you decide on Stiebel Eltron vs Ariston.

Product Overview

Stiebel Eltron produces various green tech products. This includes renewables, such as heat pumps, ventilation systems, system cylinders, and units for energy management. They also make different water filters, HVAC units, hand dryers, as well as – you’ve guessed it – water heaters.

Stiebel Eltron Tankless Water Heater -...
  • CONTINOUS FLOW – Hot showers will never be...
  • SPACE & ENERGY SAVER – Its small, sleek...
  • SILENT OPERATION – One electronic switch...

Ariston, on the other hand, isn’t as diverse. They mainly produce water heaters and heaters, as well as burners and various components for your heating units. Not only are they less varied regarding products, but they have fewer different heaters as a part of their offer. Mind you, this isn’t about their quality, just quantity.

As such, in this round of ‘Stiebel Eltron vs Ariston’, the clear winner is Stiebel Eltron.

Ariston 19 Gal POU Electric Water Heater
  • 19 gallon electric mini tank water heater...
  • Provide immediate, stored hot water at the...
  • Perfect for multiple applications: in-law...

High Water Flow Rate

When choosing the best electric tankless water heater, especially for cold climates, selecting one with a high water flow rate is imperative.

According to the U.S. Department of Energy, a household needs a heater with a water flow rate of at least 3.25 gallons per minute (GPM). Anything less than that is considered low pressure.

So, where do our competitors stand?

We’ve looked at the two of the best-selling Stiebel Eltron Tankless Water Heaters, the Tempra 36 Trend and Tempra 12 Plus. This is what we’ve found:

  • The Tempra 36 Trend manufacturer claims that the unit can reach 4.5 GPM. While this is rather impressive, many users have complained that they couldn’t get more than 2.5 GPM out of their unit.
  • It is stated that Tempra 12 Plus can reach a max flow rate of 3 GPM. This seems to be pretty accurate.

As for Ariston, we’ve looked into its most popular units on Amazon, POU Electric Water Heater, as well as Andris 8 Gallon Mini Tank. However, we couldn’t find information about the maximum flow rate of these units, or most of Ariston’s water heaters. As such, we’ll call this round a tie.


Regarding energy efficiency, Stiebel Eltron is one of the most efficient brands you can find. This shouldn’t come as a surprise, as they mostly use green energy for their units. In fact, its tankless water heaters are 99% efficient thanks to the brand’s advanced technology. If you were to use their popular DHX models, you’d find their activation rate is 0.264 GPM, which is reasonably low.

Ariston also has energy-efficient products. Even many of their water heaters with the tank will still be relatively efficient. Most of its products can save up to 70% of energy compared to regular products, and most have a point of use of around 0.5 GPM.

Just by looking at these numbers, we can see that the clear winner here is Stiebel Eltron.

Green Technology

Stiebel Eltron is a brand known for using green energy and units that help consumers reduce their energy consumption. It focuses on renewable energies and produces some of the most energy-efficient heaters (and other units) you can find.

Ariston is also known for its efficient and renewable solutions. It strives to create products that will help heat your water in the most renewable way possible, no matter the energy source.

As both brands rely mostly on green technologies, we can only say that both Stiebel Eltron and Ariston win this round.


A product’s quality is greatly determined by the manufacturer’s warranty, as this is proof of how confident the company is that its unit and parts will work properly. Of course, the materials used are essential, as well. However, most water heaters nowadays are made of stainless steel, copper, or vitreous enamel-lined carbon steel. As such, there isn’t a genuine competition in this field.

To determine the two brands’ quality, we’ll again look into the four models we’ve listed. Here’s what we can conclude:

  • Both Stiebel Eltron’s Tempra 12 Plus and Stiebel Eltron’s Tempra 36 Trend come with a 3-year warranty on parts, and a 7-year leakage warranty.
  • Both Ariston’s POU Heater and Andris 8 come with a 6-year limited warranty on the tank, while the Andris also has a 2-year warranty on parts.

The numbers clearly point to the winner. Once again, it seems that the Stiebel Eltron is a winner.

Ease of Installation


Whether you are installing your first heater or switching from gas to electric-powered units, most water heaters require to be installed by professionals. Still, the easier the installation method, the higher the chances of the procedure being quick and affordable.

The Stiebel Eltron’s Tempra 12 Plus unit is so easy to install that many users have reported a successful DIY! However, the Tempra 36 Trend, while easy to mount on the wall, requires professional services that can be costly.

On the other hand, both Ariston’s POU Heater and Andris 8 come with clear instruction manuals. They have such an easy one-person installation process that most people won’t have issues installing the units themselves. Also, they are compact and easy to fit in most cabinets and locations, making everything even more straightforward.

So, when it comes to Stiebel Eltron vs Ariston, which one is easier to install? The winner seems to be the Ariston, as it has some of the best thought-of installation processes we’ve ever seen

Related: Stiebel Eltron vs Rheem

Bottom Line

Stiebel Eltron vs Ariston – it seems that the winner is easy to determine.

The Stiebel Eltron seems to win in almost every round. This is a highly energy-efficient brand with top-quality products that very few brands can compete with. It is one of the oldest brands that puts most of its focus on renewable energy and that has used this practices in many fields, not just in manufacturing water heaters. Its products win over most of the competition, which is precisely why this is one of the most popular brands out there.

This isn’t to say that Ariston is a bad brand – on the contrary. Ariston’s products are well-made and efficient. It simply had a worthy opponent, perhaps even making this an unfair fight.

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