Onsite, stated VHL range back left burner is unit burning incorrectly. checked over, has tall yellow flames as compared to other burners. checked air shutter adjustment, found burner not placed correctly onto gas valve orifice. set burner on correctly. now is burning properly. did also find all pilot heads are deteriorating. spoke with maintenance. will order all pilots and return. 1/21/21 Replaced the pilots and holder clips on the burners .i checked ops. ok ready to use.