Honeywell Servo-combi gas valve VR420VA1004-0000

The Honeywell VR420VA1004-0000 is a servo-combi gas valve with a nominal diameter of 20 mm, designed for gaseous fuel applications. It operates at a supply voltage of 230 V and 50 Hz, with a maximum inlet pressure of 200 mbar and a flow capacity of 1 m³/h. The valve features a pressure servo controller with diaphragm, a pressure relief valve, and pressure test points. Its body is made of aluminum alloy, the filter element has a cell size of 0.34 mm and is made of AISI 303 steel, and the closing spring is AISI 302 steel. The valve plunger is coated with Fe 360, and seals are made of NBR and Viton rubber. It includes a flange kit with one flange, sealing plug, sealing ring, four screws, and one pressure measuring fitting. The valve meets EN 161 standards with Class A + A valve classification and Class C regulator classification, and has an ingress protection rating of IP40.

When selecting a replacement gas valve of this type, ensure the nominal diameter, maximum inlet pressure, supply voltage, and frequency match the existing system. Verify the flow capacity meets the burner's requirements. The valve body has flanged connections on each side, allowing installation of optional devices such as pressure switches or inspection systems. Before ordering, measure the physical dimensions and compare the flange kit configuration to ensure compatibility with the existing piping.

Common failures in gas valves of this kind include sticking or leaking due to worn seals or debris in the filter, leading to unstable gas pressure or failure to open/close properly. Symptoms may include burner ignition issues, fluctuating flame, or complete loss of gas supply. Check the filter for clogging, inspect seals for damage, and verify the electrical connections and coil operation.