Because these burners are constructed of cast stainless steel, over time you may notice the portholes are closing up due to calcification. To keep your burner working properly year after year you will want to inspect these burners each season and clean off all of the calcification with a wire brush. If you have neglected to do this grill maintenance you may notice your ports are severely clogged and you can attempt to unclog each of these ports by either drilling them out with a drill or the use of a sandblaster.