Weber BBQ Grill S-320 Instructions to Convert To Natural Gas Or Propane.

by grillrepair on

This video with instructions to convert a Weber S-320 Genesis model includes directions for converting the main barbecue grill burners and shows conversion of the side burner range and installing the regulator to the manifold and incoming gas line.

Weber Genesis manifold valve orifice and burner venturi

Weber Genesis manifold valve orifice and burner venturi

This image shows the Weber Genesis S-320 gas line connection, gas manifold, control valve, orifice, burner and venturi air-shutter adjustment.  After the conversion of the gas orifices and the regulator we need to light the grill while the control panel is still uninstalled.  While the flames are burning on all 3 burners we need to check to see blue flames approximately 1-1.25 inches long and blue with a yellow tip.

If the flames are too small or are too big and yellow we can loosen the set screw and adjust the air shutter to allow more or less air to mix with the gas as the gas sprays into the burner through the orifices we just installed.


Weber bbq grill natural gas regulator

Convert the barbecue to NG by adding an appliance regulator to the manifold connection. Use adaptors to connect manifold and gas line.



























Install a natural gas appliance regulator below the manifold when the barbecue has to be converted to natural gas.  This Weber S-320 mosel was manufactured for use with LP – liquid propane so the connection adaptor on the manifold has a 3/8 flared thread.  We will need a couple of adaptors to get from this gas line connection to the 1/2″ pipe thread of the regulator.  The other side of the  regulator may also need a few adaptors to get to the proper threading to connect to your gas line.

The regulator should be attached as shown and not 10′ away by connecting the regulator to the shut-off valve connection.  We only want the regulator to step-down the gas flow as the gas flows into the gas manifold where the gas passes through the control valves, orifices and into the burners.  If we have the regulator too far away then the gas pressure is too low to reliably feed across through the gas hose to the barbecue.


Gas fuel conversions are very simple — which is not to be confused with easy — but they need to be done correctly and safely.

For additional assistance, please contact Majestic Grill Parts:


[email protected]


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