ZVM28 Motorised Mid-position Valve - 3 Port 28mmZVM28 Motorised Mid position Valve 3 Port 28mm Motorised valves, three port mid position, 230 V AC operation with microswitch. Head assembly demountable for servicing. Industry standard synchronous motor. Either the total head assembly or the motor can be replaced when necessary. Product Specification Closed or Open Normally Open to DHW Connection 28 mm Comp. Power Supply 230 V AC Size 28 mm Type 3 Port Mid Position Valve Voltage 230 V AC