Bosch GL2.5 Ariston 2-1/2-Gallon Point-of-Use Indoor Electric Mini-Tank Water Heater Review



The Bosch GL2.5 Ariston electric mini-tank water heater is somewhere between the midline range of tankless water heaters. That being said, it is also one of the highly reviewed water heaters and comes in three models that can store up to 2.5, 4, and even more than 6 gallons of water. Created by Bosch, The GL2.5 incorporates a point of use water heater by Ariston that basically eliminates the need to have a larger storage tank.

The Bosch GL2.5 Ariston can be easily installed in-line along with a water source. We all know as a fact that Bosch makes products that are innovative and energy efficient, while Ariston makes water heaters that are durable and highly functional. And the Bosch GL2.5 Ariston is a prime example of what both companies have to offer.

Important Specs and Features

As mentioned before, the Bosch GL2.5 Ariston mini-tank electric water heaters come in three different models. The heaters featuring aesthetic at the outside layer and are glass lined inside to promote durability over the long run. It’s an easy to install and use electric water heater that is not just economical, but provides high energy efficiency and insulation as well.

The Bosch GL2.5 Ariston water heater can be easily installed under sinks and can complement your existing water heating systems as well. With consistent water pressure and a mini-tank, you can rest assure that you won’t run out of hot water even after continuous usage.

It also has a high PSI at 150, which offers consistent result at every usage. The aesthetic is basically ABS plastic, which accounts for durability and reliability over the years. The unit comes with a wall mount bracket that is designed for easy installation and flexibility. In fact, you can install it on the floor, under the sink, or on a wall, wherever you like it.

The Bosch GL2.5 Ariston can store up to 2.5 gallons of water, and as being a point of use water heater, it can supply hot water to 2 sinks at one time. It’s designed to prevent heat loss across the unit and the pipes, which allows energy efficiency year-over-year. In other words, you’re getting hot water instantly, whether at home or at your office.

The water heater is designed with titanium and inner glass lining to prevent leakage and promote longevity. It features an adjustable thermostat accompanied with a thermal cut out to easily set varying
temperature levels. All it needs is a basic 120V plug-in connection to start working. The Bosch GL2.5 Ariston is also quite compact in size, with dimensions at 14 x 14 x 10 1⁄4. And coming with an 8 year commercial or residential warranty and a one year limited warranty on parts, you know you’re getting one water heater that will definitely go the distance.


  • Easy to install and use
  • Compact design that allows it to be installed just about anywhere with a water connection.
  • Can store 2.5 gallons of water – good for emergencies.
  • Runs through standard power outlet – no additional costs in installation.
  • Users have expressed delight over longevity.
  • Highly energy efficient and heats water within 2 seconds.
  • No need to vent.
  • Fairly simple and low key maintenance.


  • Customers reported minor leaks
  • Requires a dedicated power outlet.
  • Not practical in very cold areas.
  • Additional equipment like hose may not be provided.
  • Designed for sink use – perfect for washing hands, obsolete for taking hot showers.

Who Should Buy

This is a tricky one but we’ll give you an answer nevertheless. The Bosch GL2.5 Ariston electric mini-
tank water heater is ideal for small households and offices. It can help you clean your dishes, wash your clothes, and provide hot water to make coffee at the office. If you have an existing water heating system, then the Bosch GL2.5 Ariston can compliment it to perfection.

However, there are limitations to Bosch GL2.5 Ariston water heater that you must consider before investing. First and foremost, it is designed specifically for individual sink use, so using it for showers is not an option. Another thing is that it can work ideally in regulated climates. If you’re based in some of the colder parts of the world, then you’ll be one of the many that complain that the Bosch GL2.5 Ariston can only heat water to a certain point, which is low than what the temperature range is.


If you are in the hunt for a water heater that can help you wash your dishes, clothes, or make coffee instantly, then the Bosch GL2.5 Ariston water heater is just right for you. It’s economical, energy efficient, and above all, has water storage space that other water heaters in the similar price range don’t. That being said, it does have its limitations, so consider your options wisely.