Hydraulic interface unit (HIU) for instant hot water generation

is a unit (HIU) which transfers heat from a buffer cylinder to the fresh water as it flows through a heat exchanger.The desired water temperature can be adjusted and is usually kept constant with an electronic control. Only the quantity of DHW you require at the exact moment flows through the fresh water module.

overview of different fresh water modules


  • No electronic control needed
  • with high efficiency pump and fast flow detection
  • Optionally with recirculation configuration
  • Available with flow rates of 20 and 30 l/min. 


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  • The electronic control regulates differing flow temperatures and varying volume flows so that a constant hot water temperature is achieved
  • Optimum stratification of the heating water with a speed-controlled high-efficiency pump and PT1000 sensor
  • Optionally with recirculation
  • Available with the following flow rates:
    26, 40, 50, 63, 75, 95 l/min
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  • No control and sensor technology required
  • No buffer mixing by permanentl
  • No electirc and no electronic connection required - thereby power saving
  • hot water flow up to 28l/min, depending on cold water mains pressure.
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