How to Choose a Water Heater?

How to Choose a Water Heater? After or before repairs, during a move, before the next seasonal shutdown of hot water – it does not matter at what point you decided it was time to buy a water heater. It is essential to choose the right one. In terms of energy used, water heaters can be divided into two types – electric and gas. The use of gas water heaters is limited to gasification at home, so many more electric models are more diverse.

How to Choose a Water Heater

How to Choose a Water Heater?

Electric water heaters can be divided into storage and water flow depending on the structure. The first ones have a particular container – an internal tank – inside which water is accumulated, which is then heated and supplied to the user, which is why they are called accumulative.

Flowing water heaters are arranged differently – inside the water heater, there is a small flask with a heating element. When water enters the flask, it heats up and immediately goes out. Each type has its pros and cons.

13 Criteria for the Selection of a Good Water Heaters

As already mentioned, an internal water tank is inside the storage water heater, and heating occurs due to the heating element built into the tank. At the same time, storage water heaters have many differences – from size to control features.

1. Volume

For storage water heaters, the main character is volume. To choose a suitable water heater in terms of volume, you need to know how many people will use hot water and how many points of consumption where hot water will go. You can use the following calculation formulas:

  • 1 user + 1 point = 10 – 30 liters
  • 2 users + 1 point = 30 – 50 liters
  • 2 users + 2 points = 50 – 80 liters
  • 3 users, 3 points = 80 – 100 liters
  • 4 users or more + 2-3 points = 150 liters or more

It is also worth considering the capabilities of your electrical network: for low-power networks, you can choose a water heater with adjustable power and a minimum value of 700 – 800 watts. Water heaters with a 1500 – 2500 W capacity are suitable for ordinary urban networks. For large volume water heaters, you can consider models with a power of up to 6000 W and a three-phase connection.

2. Type of Allocation

There are two possible placements for the water heater – wall mounting and floor mounting. Wall-mounted water heaters usually have a volume of up to 150 liters since larger water heaters are already safer to mount on the floor. At the same time, when installing on the wall, there are options for placing the water heater – vertically or horizontally.

Initially, each water heater model has its recommended position – vertical or horizontal- determined by the location of the nozzles, the heating element, and the control panel. There are also series with a universal installation. They can be placed both vertically and laid on their side. The water heater’s design considers such an arrangement that neither the quality of heating nor the control of the equipment will suffer.

3. Hull shape

With any placement option, the shape of the water heater body is of great importance. Initially, all water heaters were round in shape, the body repeated the outlines of the inner tank, so this shape is considered a classic.

Over time, Double Tank technology appeared – instead of one round tank, two cylinders are located inside the water heater, interconnected as communicating vessels. Thus, the depth of the case becomes much smaller – instead of 45 cm, as in a round water heater, 25-30 cm.

At the same time, the water heater’s volume is preserved, and instead of the depth, the height increases. Such a water heater protrudes less from the surface. It is easier to place it in the bathroom or the kitchen.

It is also possible to place the water heater in a corner or a rectangular niche. Models with a rectangular or square body are excellent for this. Inside such a case is one tank, but higher and narrower than the classic round one. A rectangular body can be used not only for corner placement but also for separate installation – as a round one, the depth of such water heaters is about 36 cm.

4. Inner tank type

Since water heaters are constantly in contact with water, their main problem is corrosion. The internal tanks of such equipment are made of metal, so they are immediately equipped with oxidation protection – a special coating or tank material.

5. Enamelled inner tanks

Special enamel compounds coat the steel to protect it from corrosion. The enamel is applied in a dense layer and does not allow steel contact with water. Different manufacturers have their composition and production technology. Still, all types of enamel coatings during operation require regular (at least once a year) replacement of the anode. This special rod draws the electrochemical activity of water onto itself, protecting the metal from corrosion.

At the same time, since the steel constantly heats up and cools down, due to which the metal narrows and expands, the enamel coating can crack and crumble.

However, among the enamel coatings, there is also Bioglass Porcelain – such enamel is adhesion with the walls of the inner tank, narrows and expands along with the metal since it has the same coefficient of expansion as steel.

6. Stainless steel inner tanks

Internal tanks can be resistant to corrosion due to the material they are made of. If alloying additives are added to the steel alloy, mostly chromium, nickel, or molybdenum, it becomes resistant to the chemical attack of water by itself. The biggest danger for such internal tanks is welding – if it is carried out incorrectly, then in the places of the seams, all alloying additives burn out, and the material rusts.

To create durable stainless steel tanks, various manufacturers use technologies such as G.5 – a set of procedures, including cold welding, the use of robots, and the supply of a special gas that makes tanks resistant to corrosion even at welds. Such internal tanks do not need constant anode replacement and have an extended warranty – from 7 years.

Most often, enameled internal tanks are located in a round case, and narrow appliances are made of stainless steel. It is not necessarily correct. Flat water heaters come with enameled internal tanks and round ones with stainless steel.

7. Heating element

Two types of heating elements in water heaters are dry and submersible. Submersibles are classic heating elements located inside the tank and in direct contact with water. These include copper, stainless steel, titanium heating elements, TitaniumHeat heating elements, and other heating elements. Immersion-type heating elements are made of materials with high thermal conductivity and can be equipped with corrosion protection.

On the other hand, dry heating elements do not directly contact water. They are located in unique flasks that transfer heat from heating. Flasks protect heating elements from corrosion, which makes them more durable.

It would be best to remember that the water heater’s heating element is always a consumable material. The water contains hardness salts, better known as scale, which, when heated, begin to settle around the heating element or bulb and cause local overheating, followed by microcracks.

As a result, the heating elements burn out and need to be replaced, so you should consider the price of the heating element when choosing a water heater. Dry heating elements are more resistant to scale since they can not settle on the heating circuit itself, making them more durable. Also, due to the indirect heat transfer, the heating becomes more uniform, which reduces the amount of scale and also helps to protect the heating element.

8. Control type

Management in water heaters is mechanical, electronic, and electronic-mechanical. In the latter case, some settings are usually set mechanically, and some – electronically. Each control method has its advantages. The mechanics are simple and retain the settings during power surges. The water heater is turned off from the mains, so these models are great for country houses with unstable connections.

Electronic control is usually more complex and includes several modes and additional control settings. Also, with electronic control, the temperature settings are more accurate, and the heating is shown on display. Electronic control will look great both in the house and in the apartment or office.

9. Small-capacity water heaters

Water heaters up to 30 liters are usually called small-capacity. They are installed above or below the sink. It reduces the distance between the source of hot water and its consumers. Forms of small-capacity water heaters often differ from the equipment of a larger volume. Otherwise, the characteristics of small-capacity water heaters do not differ from large-capacity drives.

10. Large capacity water heaters for floor installation

Large water heaters with a volume of 150-300 liters are needed to meet the large demand for hot water. Such equipment will be helpful in a private house, a large apartment, or an enterprise.

Floor-standing water heaters of large volume heat up for a long time, but at the same time keep the water hot for a long time, and the heated volume, as a rule, is enough for everything. There are also models with different coatings of internal tanks among floor water heaters, but all are round.

11. Criteria for selecting an instantaneous water heater

Flowing water heaters often become the only option to organize a hot water supply where it is physically impossible to place a storage water heater. In addition, flowers compare favorably with the fact that you do not need to wait until the water heats up – it is supplied hot as soon as the tap opens.

12. Number of service point

To choose an instantaneous water heater, first of all, you need to understand how many points of consumption the equipment will serve – for one point, equipment of a non-pressure (non-system) type, equipped with a spout or a shower set, is suitable. These accessories have been carefully selected to ensure good water atomization even when the heat is good. If you want to provide hot water to several points at once, a pressure-type water heater is suitable.

13. Network Capabilities

Flowing water heaters have higher power than drives, which must be taken into account when selecting – with small dimensions, the power of these devices ranges from 3 kW to 24 kW. Flowers up to 10 kW are suitable for domestic use, and 21 and 24 kW are suitable for commercial or municipal enterprises.

It is also worth considering that how much water the equipment will heat directly depends on the water heater’s power. You can adjust performance by changing the flow rate and the ability to adjust the power. More powerful models must be used if a high heating temperature is required.


Whatever water heater you choose, the main thing is that it be a quality technique from a trusted manufacturer. It is worth paying attention to the warranty period, the popularity of the brand, and its popularity – the company’s equipment, which is not the first year on the market or even is the best brand in the category, will not disappoint during operation. The built and proven service center network will help with maintenance and installation. Choose a quality water heater and fill your home with warmth and comfort.