Honeywell Gas valve VK4100C1075U

The Honeywell VK4100C1075U is a combined gas valve for burner control and ignition systems, managing gas flow for both pilot and main burners. It operates with a maximum inlet pressure of 60 mbar and a nominal inlet pressure of 25 mbar, with a flow capacity of 3.1 m³/h at a pressure drop of 3 mbar. The valve features Softlite smooth ignition with a pressure of 5 mbar and a time of 1.5 seconds, and regulates the gas-air mixture in a 1:1 ratio. It has a 3/4" external thread inlet, an outlet diameter of 18.6 mm, and a compression fitting of 4 mm. The ambient temperature range is -15 to 60 °C, and the maximum working pressure is 45 mbar. This valve fits FERROLI PEGASUS 45-56 and Pegasus (Old) 23-32 boilers, with superseded numbers 39816420 and 36802910.

When selecting a gas valve of this type, ensure the inlet and outlet connections match the existing piping: the inlet thread size and outlet diameter must be compatible. The valve's maximum working pressure and flow capacity should meet or exceed the system requirements. Check the electrical connections and voltage compatibility with the burner control. The valve must be installed upright, and the ambient temperature range must suit the installation environment. Verify the gas type (natural, liquefied, or heating) is supported by the valve model.

Common failures include the valve failing to open or close properly, leading to no gas flow or gas leakage. Symptoms may include burner ignition failure, flame instability, or the system shutting down due to safety lockout. Check for blockages in the inlet filter, diaphragm damage, or electrical faults in the solenoid. Pressure irregularities may indicate servo or pressure regulator issues.