The SF4 kit contains a 2 litre expansion vessel and check valve to prevent expanded hot water re-entering the cold water supply. It also comes with a pressure reducing valve, for areas where water pressure is high. The SF4 kit is suitable for use with small unvented water heaters such as the Hyco Speedflow unit.
• 2 Litre Stainless Steel Expansion Vessel
• 15mm Single Check Valve
• 1/2" F/F Pressure reducing valve