Clean the burner tube with a brush if the burner is clogged. Blow out the burner with compressed air. Clean the burner area of all soot and scale.
Properly install the flue baffle tube if it is not in as it should fit. Sometimes it can pop out during travel.
Blow out the burner with condensed air if it is just dirty. A dirty burner can prevent the gas from reaching the ignition.
Set the main regulator so the pressure doesn't drop below 11 inches of the water column at the pressure test port. This should be done is the gas pressure is low at the burner.
Relocate the burner if it is not sitting under the flue properly.
Replace the burner with a new one if the burner is cracked or damaged.
