HIU flexLEN, in a 4-pipe system, for maximum DHW comfort with simultaneous use in modern low-energy networks. Supply via district heating or central heat generation, with separate energy circuits for hot water and space heating. The 4-pipe system allows the station to be used for heating as well as cooling with simultaneous decentralised hot water production. Highest energy efficiency in heat supply can thus be achieved. The station uses a highly efficient heat exchanger for immediate hot water production as required in the high-temperature circuit. The room heat or room cooling is separated from this and supplied directly from the separate low-temperature circuit for surface heating or surface cooling, via an integrated, dynamically controlled heating circuit distributor. The pipe connection to the heat exchanger is made via ball valves. The pipes can be connected from below.

Consisting of:

• Copper-brazed asymmetrical stainless steel plate heat exchanger;
• HERZ pressure and temperature controller for central control of the hot water temperature;
• Constant readiness for hot water preparation even in summer operation due to temperature-controlled bypass circuit, fixed at 45 °C;
• 2 heat meter adapters 110 mm, also suitable for continuous operation;
• Warm and cold water meter adapter piece 130 mm – G 3/4", also suitable for continuous operation;
• Adapters 80 and 110 available as accessories;
• Heating/cooling supply in water vapor-tight insulated housing;
• Strainer with fine mesh in the primary supply line;
• Strainer with drain ball valve in the space heating flow line;
• Pressure-independent control in the supply line to the connected consumer;
• Differential pressure controller 25–60 kPa in the high-temperature circuit;
• Connection domestic hot water supply: MT 3/4" flat sealing;
• Connection for heating/cooling supply: MT 1" flat sealing;
• Max. operating pressure: 10 bar;
• Max. supply temperature: 85 °C;
• Min. drinking water flow pressure: 2.8 bar;
• Thermal readjustment;
• Circulation line retrofit set: 1 4028 57;
• Flush-mounted box short: 1 4025 65;
• Front frame and front door short: 1 4025 66;
• Flush-mounted box long: 1 4025 88;
• Front frame and front door long: 1 4025 89;
• Surface-mounted cover: 1 4025 67;
• Extension set for ceiling cooling: 1 4025 69;
• Extension set for pump: 1 4025 70.