Can water heaters be electric

Buying a water heater: you should know that

Types of water heaters

There are three types of electric water heaters. They differ in their control. This can be done hydraulically, electronically or fully electronically.

Hydraulic water heater

With these devices, the water flow rate determines the temperature. It becomes problematic when the shower, wash basin and bathtub are required at the same time. Then the temperature may suddenly drop because the system cannot immediately bring as much water to the desired temperature.

At the same time, most hydraulic instantaneous water heaters require at least eight liters of water per minute at the individual tap in order to switch on and deliver warm water. This is why these devices can often not be used with economy accessories, or not at all. If in doubt, you should test beforehand whether a money shower head works in your bathroom.

You can often only find out whether you have a hydraulic instantaneous water heater at home by looking at the product name on the nameplate or by asking the manufacturer. A little test also helps: Is the switching noise particularly loud and does the water only get warmer when you throttle a very strong water flow a little? If so, there is a high probability that you have a hydraulic water heater. Most of these devices also only have two switching stages.

Electronic water heater

They are usually infinitely variable. On these devices you can set your desired temperature directly and precisely to the degree. It is ideal if you no longer have to add cold water. Then you save time, water and electricity.

Fully electronic instantaneous water heater

These devices are a little more economical and more convenient than electronic instantaneous water heaters, but they are also more expensive. Their advantage is that they still deliver the desired temperature even under full load, because they simply lower the water flow when necessary.

Pay attention to low energy consumption

The energy efficiency label is intended to help you make a purchase decision. All instantaneous water heaters that are new to the market receive the EU label and thus a classification in a certain energy efficiency class. The seven efficiency classes are classified according to the traffic light system, with a green bar for the best efficiency class A + and a red bar for the worst efficiency class F. A black arrow next to a colored bar shows the efficiency class of the device.

If you are looking for an economical device, look out for the A + rating for water heaters.

Water heaters can achieve a better rating if they are connected to a solar system or a hot water storage tank. An A +++ label is provided for this.

How the electricity consumption of an instantaneous water heater is to be estimated is provided by the concrete information on the annual consumption on the label. Because even within an energy efficiency class, the consumption of individual devices can vary greatly. It is possible that a hydraulic instantaneous water heater, like an electronic one, receives the A rating. In everyday life, however, an electronic device can save up to 30 percent electricity because it automatically adjusts its power consumption and thus energy consumption to the amount and temperature of hot water.

The tap profile on the label provides an indication of which application the device is suitable for. It doesn't make sense to heat a relatively large amount of water with a powerful instantaneous water heater if you only need small amounts. For example, a mini instantaneous water heater with an XXS tap profile is sufficient for a hand washbasin. This is also well suited to replace a classic undercounter device, in whose water tank usually a few liters of water are always kept warm. If you would like to supply several draw-off points in the bathroom or in an apartment with one hot water device, a larger instantaneous water heater with the tap profile S is suitable.

Instantaneous water heaters are usually not particularly loud. The specified noise level can play a role when purchasing if the water heater works in combination with a heat pump. A clock on the label indicates whether the device is suitable for exclusive operation with a low-cost low-load tariff (night tariff). This information is usually not relevant for the electric instantaneous water heater, but rather intended for water heaters with storage volume. You can clarify further questions relating to your personal household situation in an energy consultation.

Advantages and disadvantages of water heaters

One advantage of instantaneous water heaters is that they only heat the water when it is needed. As soon as a tap - i.e. a tap or a shower fitting - is opened, the instantaneous water heater starts its service. And only then does he consume electricity. Therefore the setting N or 0 is not available. The device is running or not running.

Since these devices do not store water, there is no heat loss. Nevertheless, instantaneous water heaters are not always the most cost-effective option for heating water when in operation. Because electricity is more expensive than oil and gas, for example. But there are a few tips on how you can reduce the costs of hot water with an instantaneous water heater.

Instantaneous water heaters are mainly used when the tapping points in the apartment or house are far apart. Instantaneous water heaters are also advantageous when water consumption is low, for example in a holiday home.

How efficient a water heater should be depends on the planned use. In order to comfortably heat shower water, the device should have an output of around 21 kW. In the case of devices with a lower output, the flow rate may be limited. It is best to ask your installer. When installing, he must also consider the existing cable cross-sections of the power cables. The devices are normally maintenance-free and do not have to be vented. If there are problems, only have repairs done by experts.

This content was created by the joint editorial team in cooperation with the consumer centers North Rhine-Westphalia and Rhineland-Palatinate for the network of consumer centers in Germany.