Kromschroder Gas solenoid valve VG20R02NT31D 85206030

This solenoid gas valve is designed for automatic shut-off of gas and air flow. It is normally closed and closes when power is off. The valve is certified to EN 161 Class A. Its nominal diameter is 20 mm and it has an internal Rp 3/4 thread connection, with a maximum inlet pressure of 200 mbar. It operates at 220–240 V AC, 50–60 Hz, and offers quick opening and closing. The housing includes a terminal box and has IP54 protection.

Parts of this type are selected by brand, connection size, coil voltage, and function variant. Connection sizes typically range from Rp 1/2" to 2" or flanged, and common coil voltages are 230 V or 24 V AC/DC. The coil is usually replaceable separately from the valve body. When replacing, ensure the new valve matches the original's connection size, coil voltage, and function type, and confirm that the mating gas pressure switch and burner control are compatible.

Common failure modes include coil burnout, leaking seat, drifting outlet pressure, and a seized servo regulator. When the coil burns out, the valve may fail to open, preventing gas flow. A leaking seat allows gas to pass in the closed position, which can lead to dangerous conditions. Drifting outlet pressure results in unstable burner operation. A seized servo regulator can cause the valve to stick. Check the coil resistance, test for seat leakage, and measure outlet pressure to diagnose these issues.