Domestic hot water heat pump (hot water heat pump)

A domestic hot water heat pump only heats your hot water. It is usually mounted directly on a cylinder and uses the heat from the indoor or outdoor air.

A domestic hot water heat pump, often also called a heat pump cylinder, is a separate small appliance just for hot water. As a rule, it is an air-to-water heat pump that is permanently mounted on a hot water cylinder. It gets its heat either from the air in the installation room or from outdoors via pipes. According to klimaaktiv, such devices have been in use for more than 40 years.

When this is of interest to you

• With a biomass or district heating system: In summer, the domestic hot water heat pump produces the hot water, so the boiler can remain switched off. In winter, the cylinder runs alongside the heating system.
• Instead of an electric hot water cylinder: klimaaktiv recommends a hot water heat pump or solar thermal system over direct electric heating, as this saves energy and operating costs.
• Together with a space heating heat pump: According to the Bundesverband Wärmepumpe (German Heat Pump Association), a separate hot water appliance can increase efficiency because the space heating heat pump does not have to run at all in summer.

What you should look out for

If you place the appliance in a room, it cools this room down slightly. This is often desirable in a cellar, but less so in a living space. Together with a photovoltaic system, solar power can easily be stored as hot water.

You can find out more about the correct cylinder size and temperature under hot water cylinder and legionella protection.

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