On Bull Outdoor Products grills equipped with an Infrared Backburner…
Make sure the gas is on.
Turn the knob slowly but stop before the ignition snaps, when you stop, hold the knob for 7-10 seconds. This allows the gas to flow thru the Infrared Backburner for 7-10 seconds allowing the gas to migrate to the opposite side of the Backburner where the ignition is located.
After doing so proceed turning the knob to complete the snap.