Honeywell Home Differential Bypass Valve 22mm – DU145B

Honeywell Home 22mm Differential Valve By-Pass DU145B. This valve is part of the Honeywell Home range and controls flow of water through a bypass circuit which is installed between flow and return pipework, typically at or near the boiler. The DU145 saves energy by only allowing flow through the bypass when needed i.e. when flow through the system is reduced when zone valves or radiator thermostats are closing.