FillingCombi BA – With shut-off valve, pressure reducing valve, double pressure gauge, BA backflow preventer and drain connection, the FillingCombi BA includes all Components required for safe heating system filling and enables automatic filling and refilling at thecdesired operating pressure. The SYR FillingCombi prevents back pressure and backflow of heating water into the drinking water system. The integrated backflow preventer complies with DIN EN 1717 and offers a permanent connection between the heating system and the drinking water installation. Up to and including fluid category 4.