CE-ZVD28 - 28mm 3 Port Diverter ValveZVD28 Motorised Zone Valve 3 Port 28mm The ZVD range 3 port spring return valve has been designed to control the flow of water in domestic central heating systems, where both the radiator and hot water cylinder circuits are pumped, on a selective priority basis. Product Specification Voltage: 230Vac Power consumption: 6W Cable length: 1 metre 5 core Fluid temperature: +5 to +88C Max ambient temperature: +52C