WWK 221 and 301 electronic flexible in every respect

New domestic hot water heat pumps take air from anywhere

The new DHW heat pumps WWK 221 electronic and WWK 301 electronic by Stiebel Eltron offer a high degree of flexibility.

Whether from the installation room, an adjoining room or from outside: the new hot water heat pumps WWK 221 electronic and WWK 301 electronic from Stiebel Eltron offer a high degree of flexibility at installation. The possibility of being able to connect air ducts directly to the new hot water heat pumps for the air intake and air output, means that waste heat for instance from an adjoining room or from the air outside, can also be used for hot water heating purposes. Furthermore, the duct connection can be either completely horizontal or vertical or a combination of both which in turn offers the greatest level of flexibility for installation and arrangement in the installation room.

The new WWK electronic is available with a 300-litre storage capacity or as a more compact design with a 220-litre storage capacity for smaller households and as a problem solver for confined spaces. Both storage capacities offer maximum hot water convenience at high levels of efficiency and are perfectly adequate for supplying hot water to several draw-off points in detached houses. At the same time, in recirculating-air mode, the cellar is continuously dehumidified throughout the year, and laundry hanging up dries more quickly. Colder expelled air which is produced during the process can for example also be used for the temporary cooling of a store room.

The easy-to-use electronic control unit with LCD provides the finishing touch to the equipment. The compressor is encapsulated and does its job whilst being sound-proofed from the airflow so that the appliances run very quietly. In addition to the technical specifications, the hot water heat pump impresses with its modern design and highest degree of efficiency. The appliances easily meet the requirements of the ErP regulation applicable from September 2015, as well as the conditions for highest energy efficiency class which will apply from September 2017 for hot water heat pumps, namely A plus.


A WWK electronic can be installed virtually anywhere near a socket or central hot and cold water supply pipe. Even in efficient heat pump mode, the appliances can reach hygienic hot water temperatures up to 65 degrees without the need for additional heating. The low heat source application limit of the appliances permits ventilation air temperatures up to minus 8 degrees in heat pump mode.

A special version – the WWK 301 electronic SOL – also has an additionally built-in bare-tube heat exchanger for the possible connection of an additional external heat generator such as for instance a solar thermal energy system or heating system.

A hot water heat pump is the easiest possible way to benefit from regenerative energies. An enhancement would be to combine it with a photovoltaic system. That way the self-generated electrical energy could be used back in the house again. It’s worth it: because the electrical energy generated from your own rooftop is considerably cheaper nowadays than the expensive electrical energy bought from utility companies.

The WWK electronic is SG-ready. The label is issued by the Federal Association for heat pumps to series where the control technology permits integration of the individual heat pump into an intelligent power grid. With an appliance like this, the user can be certain that he is installing a heat pump which will be compatible with future energy policy requirements.