Reliance 22mm 2 port motorised valves are used to zone your homes heating. Allowing independent control of your underfloor heating system and homes central heating. Reliance 250-305 22mm Motorised valve, two port zone normally closed, 230 V AC operation with microswitch. Pre-wired Head assembly demountable for servicing. Industry standard synchronous motor. Either the total head assembly or the motor can be replaced when necessary. Is used for a 'S' plan valve to control your heating system independently using a 3 amp switch.