Honeywell DU145 3/4B Automatic Bypass Valve, Gold

Plumbing Superstore

This automatic bypass and differential pressure valve from Honeywell Home maintains constant differential pressure in your heating system. It reduces flow noise when thermostatic radiator valves are closing. It raises the boiler return temperature to prevent corrosion from flue gas condensation. It ensures proper operation of temperature compensating controls when radiator valves are shut. For gas-fired water heaters, it guarantees minimum flow circulation when thermostats or radiator valves are shut. Features include a simple adjuster knob for differential pressure setting, easy installation between flow and return pipework, corrosion prevention, flow noise reduction, no need for external controls, and setting read directly from the indicator scale in meters water column. Honeywell Controls DU145 3/4B.. Honeywell Home Differential Bypass Valve - 22mm

City Plumbing

The Honeywell Home DU145 automatic bypass valve controls the flow of water through a bypass circuit which is fitted between flow and return pipework, typically at or near the boiler. Building Regulation advice states that if a bypass is installed, an automatic bypass valve must be fitted. It also saves energy by only allowing flow through the bypass when needed, which is, when flow through the system is reduced when zone valves or radiator thermostats are closing.