What should I do if only part of my gas burner shows a flame?
If your burner is only partially lit, it could be because it is clogged. Be sure to turn the burner off, then use a small-gauge wire or needle to clean its openings.
A partial flame might also be caused by moisture remaining in the burner after it has been cleaned. If you think this might be the case, lightly fan the flame and allow the burner to operate until the flame is full.