32. The grate. If one wants to use the grate [the iron piece upon which the pot sits] he uses all year round, ideally it needs libun (רמ"א ס"ד ) after getting cleaned from any bits of chametz. Libun kal suffices, because even if chametz spilled onto the grate, it can be assumed it got burned off by the fire. Bedieved if one used it without libun, it does not become forbidden (מ"ב סקל"ד ).
33. Some say that our grates, which extend further than the fire does, must undergo libun chamur on their whole surface, since we are concerned that chametz spilled on a part that the fire does not touch (הגר"ש וואזנר, קובץ מבית לוי ח"א עמ' כט ).
34. Sometimes, the grate's coating gets ruined by libun chamur. If one is afraid of this, he may not do libun at all (שו"ע סי' תנא ס"א ). Therefore, it is best to buy new grates for Pesach.
35. If a proper libun cannot be performed, one may cover the entire surface of the grate with thick aluminum foil in such a way that the pot does not touch the grate at all.
36. Burners. The burners, from where the fire comes out, must first be cleaned from bits of chametz. Then one should leave the flame on for approx. 15 minutes. This constitutes libun since the fire encircles the whole burner (מו"ר בשיעורי קנה בשם פ"ד אות מג ).
37. Stovetop. The stovetop must be cleaned well from any bits of chametz. Then it must be kashered through irui kli rishon, since any chametz that spilled there was through irui kli rishon. However, since it's generally impossible to remove all the gunk, especially from the crevices and the like, the stovetop should also be covered with thick aluminum foil.
38. Another way to kasher a stove is to place a metal sheet [a blech] on the four burners and then to turn all four burners on a high flame for a half hour. Then it can be assumed that anything underneath is kashered. However, it's always better to also cover the surface.
