Heating system Therma with low-limescale 3-spiral construction of heater elements in the heating rod are made of high-quality stainless steel. Direct temperature measurement in the heating rod, integrated overheating protection and effective heater control with full-load cycle are energy-saving factors which enable a high degree of heating efficiency. The bronze pump, which was specially designed for circulation and heat circuits, is designed for a ring main system of up to 225 m length (Therma 3.0) and 6 m height difference, the more powerful version Therma 4.5 is designed for 375 m and 12 m height difference. (0,5 m3/h and 3/4 Inch Pipe)