2 Port 22mm or 28mm Motorised Zone Valve Head Can Replace Honeywell V4043H1056
2 Port 22mm or 28mm Motorised Zone Valve Head Can Replace Honeywell V4043H1056 V4043H1106 V4043C1156 V4043H1007 V4043H1080. Valves made after 1987 can be identified by a bump on the top of the powerhead British gas no. 378452.