The filling assembly consists of a pressure reducing valve, hose connection, and shut-off and check valve. It is permanently connected to the heating system and automatically replenishes the necessary water when needed. The check valve prevents the backflow of heating water into the drinking water system. The valves are made from high-quality dezincification-resistant brass. The sealing is made from elastomer and is highly resistant to aging. The diaphragm is reinforced with polyamide.