The hydraulic interface unit from Austria

This hydraulic interface unit heats up cold fresh water in accordance with the instant hot water principle. In contrast to a traditional hot water cylinder or boiler, fresh hot water is prepared and used at the same time. Only when hot water is needed is it heated to the desired temperature. Stockpiling over the course of days which is causing the problem of legionella bacteria is not possible anymore.

The energy for domestic hot water is supplied by a buffer tank, which can be heated by various systems – by solar power units as well as by a pellet boiler, woodfired boiler, traditional oil/gas boiler, heat pumps or other systems. High-efficiency pumps ensure the right volume flow from the buffer to the stainless steel plate heat exchanger.

  •  Freshwater module with an electronically controlled high-efficiency pump

  •  Optional for SOLARFOCUS ecomanager-touch or with independent control

  •  Ideal for combination with solar power systems and biomass boilers

  •  Circulation and premix valve that can also be integrated optional

  •  Output capacity 20, 30, 40 and 50 l/min

The fresh water module FWMkonvent combines premium components with intelligent controller. In order to be able to guarantee a consistent output temperature at the hot water tap, even with differing tapped quantities and buffer temperatures, the rotary speed of the volume flow from the buffer is regulated using a high-efficiency pump with the aid of a powerful controller. The controller receives the information required to regulate the system from a volume flow sensor or a volume flow encoder and extremely fast temperature sensors, which are able to record the smallest deviations in temperature immediately.

The adjustments to the volume flow from the buffer, and the very good heat transfer in the stainless steel plate heat exchangers, mean that the return flow temperatures in the buffer are very low. The low return flow temperature ensures ideal operating conditions in solar power systems, heat pumps or condensing boilers. An optimum level of efficiency is guaranteed.


  1. Stainless steel plate heat exchanger
  2. Speed-regulated high-efficiency pump
  3. Volume flow sensor/ volume flow encoder
  4. Buffer tank flow 1”OT
  5. Buffer tank return flow 1“OT
  6. Cold water input 1”OT
  7. Hot water output1“OT
  8. Ventilation valve
  9. Rinse and purging valves for drinking water
  10. Controller (ecomanager-touch / separate)
  11. Premix valve (optional)
  12. Circulation (optional)
  13. Rinse and purging valve, circulation
  14. Safety valve, 8 bar, circulation


Fresh water modules FWMkonvent