1. Find out what water heaters are

Find out what water heaters are
Electric models from Electrolux and Timberk, gas water heater from Ladogaz

There are electric and gas water heaters. The latter are usually called speakers and are rarely installed because of the heap of requirements for the premises. So let’s focus on the first. They are divided into flow and storage.

Instantaneous water heaters

How to choose an instantaneous water heater
Instantaneous water heater Clage CEX 9 E-compact

They are based on a spiral heater enclosed in a small heat exchanger. The device turns on when the tap is opened and instantly heats the water passing through it. After closing the mixer, a special sensor turns off the heating element.

In budget models, the heating temperature is regulated hydraulically, by reducing or increasing the pressure. The larger the jet, the faster the water passes through the heat exchanger and, accordingly, the less time to heat up.

Really hot water can be obtained only by reducing the pressure to a thin stream.

Expensive flowers boast an electronic control mechanism and heating elements with variable power. Such devices allow you to adjust the temperature regardless of the pressure. True, it will still be less than that of boilers.

What to buy

Storage water heaters

How to choose a storage water heater
Storage water heater Thermex Ceramik 30 V

These are containers with a heating element and a thermostat that heat water to a predetermined temperature. They are often referred to as boilers.

The thermal insulation layer makes the tank look like a thermos, and once heated water remains hot for a day or more. Unlike flowers, the boiler does not work instantly: depending on the volume, it takes from 40 minutes to 2-3 hours for initial heating. But then the water is heated as it is consumed, and there are no more delays.

What to buy

2. Assess free space

This is probably the most important parameter that directly affects the choice.

Large storage water heater Stout for 200 liters and a flow-through heater-faucet Electrolux
Large storage water heater Stout for 200 liters and a flow-through heater-faucet Electrolux

Tankless water heaters take up the least amount of space. The most compact versions are almost the same size as a conventional mixer. Wall models are comparable to the dimensions of hand dryers.

If free space is running out, your choice is an instantaneous water heater.

Due to the water tank, boilers have more impressive dimensions. Miniature models of 10–15 liters can be placed under the sink or in a cabinet, but devices with a volume of 50–80 liters resemble a medium-sized barrel. These take up almost the entire wall and may not fit in a small bathroom.

What to buy

3. Check connectivity

Before choosing a water heater, check the connection
Flowing electric water heater Timberk WHEL-7 OSC for outlet

You can connect to a regular outlet – subject to modern wiring with grounding – water heaters with a power of not more than 3.5 kW. Almost any boilers fit into this border, but it’s more difficult with flow-through ones.

Only the simplest versions in mixer format have permissible power. More productive models are equipped with heaters of 5-8 kW and above. And to power them, you will need a separate cable with a cross section of 4 mm² or more, laid from the switchboard.

The boiler can be installed and connected in almost any apartment. Protochnik in old houses can be a problem.

In addition, the allocated power of electricity for the apartment is important. In old buildings like Khrushchev, it ranges from 1.5 to 3 kW, in fresher sockets – 5 kW, and in apartments with electric stoves – 7 kW. And only in new buildings can reach 15 kW.

What to buy

4. Count the number of draw points

How to choose a water heater: count the number of draw points
Instantaneous water heater under the kitchen sink Stiebel Eltron DCE-C 10/12

As a rule, instantaneous water heaters are designed for use at one point, such as a washbasin. More powerful devices that cut into the water supply are able to provide hot water for washing and showering, but at the same time they are demanding on the connection line and are much more expensive.

With the right storage capacity, you can wash dishes and take a shower or even fill a bath at the same time.

What to buy

5. Consider the heating rate

How to choose a water heater: consider the heating rate
Boiler Ariston ABSE VLS PRO INOX PW 30 with accelerated heating mode

Powerful heating elements in flow heaters allow you to bring water to the desired temperature almost instantly: after 20–25 seconds, instead of cold water, warm water will come out of the tap.

Boilers are exactly the opposite. Due to the heating elements of low power, the initial heating takes a long time. For 15 liter tanks it is about 40 minutes, for models with a capacity of 80 liters it is about 3 hours. Then the heating occurs automatically and imperceptibly.

If you need hot water a little and not so often, choose a flow model. In other cases, the boiler will be more profitable.

What to buy

6. Don’t Forget the Temperature

When choosing a water heater, do not forget about the temperature
With such a pressure and a special nozzle, the flow-through heater-faucet is capable of delivering 38 ° C. Frame: ZikValera / YouTube

Manufacturers of flow models indicate a maximum temperature of 60 ° C, but in practice something comes out around 40 ° C. In this case, the set temperature can strongly depend on the pressure drops in the pipes.

Boilers calmly heat up to 75 ° C. The set temperature can only be lowered at an increased flow rate, when part of the accumulated hot water has been used and new water has not yet appeared.

At the same time, both types of water heaters depend on the temperature of the cold water at the inlet. In summer it is about 15 °C, and in winter it drops to 5 °C. And if the boiler just needs more time to heat up, then the power of the protochnik may not be enough at all.

What to buy

7. Estimate the power consumption

Since the water is heated immediately in the flowers, they are equipped with very powerful heating elements. Even in the simplest model there will be a heating element of 3.5 kW, not to mention more productive ones, where this figure is 5, or even all 8 kW.

Which water heater to choose: Gorenje TGR 50 NG B6 boiler heats water up to 75 °C
Boiler Gorenje TGR 50 NG B6 heats water up to 75 °C

In boilers, water is heated slowly. Therefore, even in devices with a storage volume of 100–200 liters, heaters of more than 2 kW are rarely installed. And in some versions of the heating element, it is even 1.5 kW.

Due to the lower power of the heating elements, electricity bills when using a boiler, all other things being equal, will be lower.

What to buy

8. Decide on a budget

Prices for instantaneous water heaters start at 2,000 rubles for mobile versions in the form of mixers and reach 50,000 rubles for stationary models that cut into the water supply system and work for two or three points of analysis.

How to choose a water heater: decide on a budget
Instantaneous water heater Atmor Lotus 5 and storage Royal Clima RWH-GA30-RE

Budget storage heaters cost from 3,000 to 20,000 rubles. A miniature boiler for 25–30 liters will cost about 6,000 rubles, versions for 80–100 liters will cost from 11,000 rubles.

If the budget is limited, a compact instantaneous water heater will be the most profitable purchase.

What to buy

Briefly about how to choose a water heater

An instantaneous water heater is right for you if:

  • there is very little space in the bathroom;
  • the apartment has new wiring;
  • hot water is needed only in one place – either in the kitchen or in the bathroom;
  • do not want to wait a long time;
  • only water heating is needed and mainly in summer;
  • water is rarely heated and energy consumption is not important;
  • don’t want to spend extra money.

A storage water heater is right for you if:

  • there is enough free space or you do not mind installing a boiler in the toilet;
  • the allocated power per apartment is low, and the wiring is old;
  • you need a full hot water supply for the kitchen and bathroom;
  • the amount of hot water is more important than the rate of its heating;
  • you like hot water, not lukewarm;
  • you use hot water often and want to save on electricity;
  • the budget for the purchase is medium or unlimited.

This article was first published in August 2019. In July 2022, we updated the text.