Instantaneous water heater comparison 2018

Purchase advice on the instantaneous water heater comparison or test 2018

  • A water heater heats the water - as the name suggests - when it passes through the unit. The cold water is heated by flowing along warm lamellae or heated by flame.
  • A distinction is made between the different instantaneous water heaters based on their design. There are electronic water heaters and gas water heaters.
  • Instantaneous water heaters provide unlimited hot water and are very environmentally friendly as they only heat up the amount of water needed and do not store and keep it warm for long.

Instantaneous water heater comparison 2018: heater

Whether in the kitchen or in the bathroom: in 2018 we are used to turning the tap on and getting warm water immediately. For us water is as good as always available.

According to a survey commissioned by the Vaillant Group, one resident in Germany consumes around 1,100 liters of water a week alone for bathing and showering, Add to that the water for cooking, drinking or rinsing.

But before this warm comes out of the pipe, it must first be heated up. This can be done in two ways: with the help of a water heater or a boiler. What the difference between these two devices consists of and what you should look for in a water heater comparison is explained in the following text.

1. What is a water heater?

To supply a house with hot water, various systems are possible: centralized or decentralized.

Instantaneous water heater comparison 2018: 2018

Instantaneous water heaters allow limitless warm tap water.

The water heater is a decentralized technical system for heating the water, Depending on the household, it is either powered by electricity or by gas. The electric instantaneous water heater is installed close to the faucet or shower, from which the hot water is then to flow.
Particularly suitable is the connection of a water heater where hot water is constantly consumed.

Convenient instantaneous water heaters are small instantaneous water heaters that can be purchased for less than 100 euros. More powerful water heaters cost on average between 200 and 1,000 euros. As with so many things, here too: the higher the performance, the higher the price.

Function of a water heater

In a water heater, the water is - as the name implies - heated in the flow. The cold water flows in loops through the plant. To heat the water, the water heater lowers the water pressure and first reduces the amount of water that is to be heated.

Now, during the flow, the cold water is heated to the pre-set temperature, for example by an integrated heating block.

This means that the water must first be heated as soon as the consumer turns the tap to "warm". Therefore it will take a few secondsuntil heated water gushes out of the tap.

2. What types of water heaters are there?

The way in which the water is heated by the construction of a water heater depends on how it is operated. Therefore, water heaters can be classified by their modes in the following categories:

Electronic instantaneous water heater

Instantaneous water heater comparison 2018: water

Electric water heaters are powered water heaters, Due to different construction methods and the type of temperature control they can be divided into three different types:

Instantaneous water heater with

  • hydraulic control: They only heat the water above a certain minimum flow rate. If the cock continues to be turned on, further heating takes place gradually.
  • electronic regulation: They are more expensive than models with hydraulic, simpler controls and have better efficiency. The water temperature can be set in advance and the heating is infinitely variable. The power savings compared to a device with hydraulic control is around 20%.
  • Engine valve control: Here, the amount of water is regulated by an electronically controlled flow valve, so that the water remains the same temperature within a certain range.

These are available in different capacities, expressed in units of kilowatts (kW). For example, there are instantaneous water heaters with 18 kW, instantaneous water heater with 21 kW or instantaneous water heater with 24 kW, Half of the rated output gives the approximate warm water run per minuteat 24 kW, that is around 12 liters per minute.

Gas water heater

Instantaneous water heater comparison 2018: instantaneous

Gas water heaters are not as common as electronic instantaneous water heaters.

  • Heating the water: via slats made of metal; are heated by burner flame
  • at high power connection to chimney necessary
  • are rarely installed as sole water heaters
  • commonly used in combi-thermoses
  • then serves at the same time the hot water preparation for heating and drinking water

combi boiler

Instantaneous water heater comparison 2018: comparison

Kombithermen are used for simultaneous hot water preparation for commercial and drinking water.

  • mostly powered by gas
  • heats drinking water for faucet by means of instantaneous water heater
  • Domestic water for heating is heated by the heating circuit
  • Installation takes place at the place with highest hot water consumption

What advantages and disadvantages a water heater in general brings, we have listed here for you:

  • permanently provides unlimited hot water
  • only heats the required amount of water
  • short lines save energy
  • built small and compact
  • no legionella danger
  • Tapable hot water volume is limited by the size and the heat output
  • takes a few seconds to deliver warm water
  • cheap night stream can not be used

What is the difference between a water heater and a boiler?

Water heaters work practically always only when acute hot water is neededbecause the water is only heated while passing through the system.

A boiler on the other hand represents a hot water tank. It keeps the once warmed up water up to 100° Celsius warm for a long period of time. So hot water is permanently in stock and can be taken immediately from the tap.

3. You must pay attention to this when buying a water heater

3.1. design type

Instantaneous water heater comparison 2018: water

Open water heaters usually find space directly under the tap.

Water heaters are either closed (flameproof) or open (pressureless).

The closed water heater

The closed heaters can store cold water inside themto heat it up faster then. This gives the possibility to place the water heater further away.

The open water heater

Instantaneous flow heaters do not store cold water. Therefore, the cold water must first be passed to the pressureless water heater, the consumer turns on the faucet for hot water. Thus, short lines are beneficial. Therefore, the open water heater is often attached directly under the tap, for example, under the sink in the bathroom.

3.2. heating capacity

The instantaneous water heating capacity is expressed in kilowatts (kW). So find somewhere the description "water heater 18 kW", this says that the heater has 18 kilowatts of rated power. The higher the power, the faster the water is heated and the more connections can be supplied, for example, with a Stiebel Eltron instantaneous water heater.

In order to be able to connect several tapping points to one device, at least 12 kW are usually required.

3.3. Mounting

Instantaneous water heater comparison 2018: heater

Gas water heaters can also be used in the garden: here, for example, for the garden shower.

Instantaneous water heaters can be installed in two different ways: on the wall or under the table. It means "under the table" that the heater is mounted directly under the tap, so for example under the sink or sink.

Which of the two variants you choose depends primarily on your living situation. Basically, however, it can be said that closed instantaneous water heaters do not have to be in the same room as the tapping point. On the other hand, open heaters should be as close to the tap as possible and are therefore usually placed in cupboards or under tables in the same room.

3.4. Temperature range

Each instantaneous heater heats in a specific heat range. Therefore, the manufacturer specifies the minimum and maximum number of degrees to which the device can heat the water.

While powerful appliances can heat the water up to 60° Celsius, others only manage to reach 35° Celsius. That's tepid then hot. Take a look at this information before you order, for example, a Siemens instantaneous water heater.

4. One should pay attention to this with water heaters

4.1. For which applications water heaters are suitable

small water heater:

They are well suited in the bathroom for that hand basin, Such mini water heaters provide taps with low water consumption at medium temperature.

Compact Heater:

Instantaneous water heater comparison 2018: 2018

Quite inconspicuous, water heaters can also be installed in modern bathrooms.

A compact instantaneous water heater is for examplein the kitchen for the sink in the right place. Because these devices are designed for a medium need for warm water at high temperature. But they can also connect the water heater in the bathroom, for example, to supply several sinks.

Instantaneous water heater with high performance:

To connect these water heaters is useful everywhere, where you want to equip several taps in different rooms with high hot water demand at high temperature. For example, the water heater for the shower and the kitchen supply.

4.2. Assembly

On Gas water heater is - as the name implies - connected to the gas line of the household.

at electric water heaters please note the following:
Some instantaneous water heaters require so much power that they can not be plugged into the wall outlet. Since some specimens do not work with the operating voltage of 230 volts but of 400 volts, they are connected directly to the high current.

In the meantime, the technology has progressed so far that there is also a large selection of continuous-flow heaters with 230 Volt operating voltage on the market. Thus, these can be easily connected to the power outlet, With a little expertise, 230V instantaneous water heaters can also be installed by yourself.

4.3. maintenance

Power Saving Tip

Durchlaufbegrenzer for faucets or shower heads reduce water flow by about half. Thus, the electricity costs are reduced because less water has to be heated. Above all, the instantaneous water heater reaches its performance limit only later.

Even the best water heater does not last long if it is not checked regularly. Regardless of the type of water heater, you should make sure that the pipes do not calcify, If these are dirty, the device needs more power to heat the water in the pipes, since the lime must first be heated before the water gets warm.

But one can say in principle that an annual maintenance with an electric instantaneous water heater with 24 kW must be carried out no less strict than, for example, with a gas water heater with 24 kW.

Because with the copies with gas you should have the combustion chambers cleaned by experts at least once a year. For example, if you own a Glage water heater, simply contact the Glage Customer Service.

4.4. safety equipment

Some water heaters are equipped with some Additional functions that protect not only the apparatus but also humans. So pay attention to these setting options in your water heater test.

For example, with a water heater in the kitchen or with a water heater, it can be useful for the shower in the bathroom, if this one equipped with a scalding protection is. This allows you to set the maximum temperature that the Siemens instantaneous water heater can reach, for example, so that it will not be unpleasant for you.

Instantaneous water heater comparison 2018: 2018

This water heater is very narrow and compact, so it can be mounted directly above the sink.

For example, Glage instantaneous water heaters are designed in such a way that splash water can not harm the appliances. So it is not a problem if the water heater is placed next to the shower.

Many devices available on the market - including the Stiebel Eltron instantaneous water heaters - have a standard built-in overheating protection. This means the devices turn off automatically as soon as they get too hot. This protects the technique and the instantaneous water heater with e.g. 21 kW lives longer.

5. Water heater or boiler: what is better?

The advantage of a boiler is that the consumer constantly has a uniformly warm amount of water available and he does not have to wait until the preparation. The big disadvantage of a hot water boiler compared to a water heater is the power consumption. The hot water tank requires significantly more electricity every year, as the water is constantly heated and kept warm.

Once the hot water tank of the boiler is empty, there are long waiting times until the water is warm again. Thus, it can happen that after a hot bath not enough water for a hot shower is available. This case will not happen with a water heater. In addition, a modern instantaneous water heater is more efficient than a hot water boiler.

If you want to buy a water heater or boiler, this is especially recommended if no central water supply exists.

6. Instantaneous water heater at Stiftung Warentest

In its issue (01/2015) Stiftung Warentest has carried out a water heater test with 20 devices. Test winners were the following electronic instantaneous water heaters:

  • 1st place: Clage DLX Electronic 21
  • 2nd place: Stiebel Eltron DHB 21 ST
  • 3rd place: Vaillant Electronic VED E 21/7

As there are a lot of manufacturers and brands of instantaneous water heaters on the market, we have listed the most popular ones here:

  • Stiebel Eltron
  • Clage
  • AEG
  • Siemens
  • Eccotemp
  • Glage
  • Thermoflow
  • Perfect
  • Brawler
  • Vaillant

7. Questions and answers around the topic of instantaneous water heaters

7.1. How does a water heater work?

With an electric booster heater, the water is heated while flowing through the structure of the water heater. This happens with the help of heating rods, which are heated by electric current.

Instantaneous water heater comparison 2018: water

Water is passed through the water heater via the connection to the cold water pipe where it is heated by electrically operated heating rods.

7.2. How much electricity does a water heater consume?

The power consumption of a water heater depends on many factors: the personal use, the construction, the amount of hot water consumption and the condition of the device.

As an approximate guideline, you can assume about 500 kWh of electricity per person per year. With an electricity price of about 27 cents per kWh, that's about 135 euros per person per year. But that's just a rough estimate. Depending on the age and efficiency of the water heater and the personal showering behavior, this number can vary greatly.

The water heater power consumption and thus the water heater costs can be easily reduced with a few tricks, for example:

  • shorter showers
  • use less water while bathing
  • Turn down the temperature control

7.3. How do I connect a water heater?

As a rule, you should have this task performed by a specialistwho also did the buying advice with you. If you still want to try it yourself, the following video explains in steps how to install an electronic instantaneous water heater:

7.4. How long does a water heater last?

Depending on the quality and processing of the water heater, the service life can be between 10 and 20 years. High-quality equipment, which is regularly maintained and decalcified, can last even longer.

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