==Which materials can be kashered?==
# It is possible kasher wooden, metal, or stone utensils. It is impossible to kasher earthenware utensils. <ref>Kitzur Shulchan Aruch 116:1-2</ref>
# Hagalah includes cleaning the pot well from all Chametz, then immersing it in (boiling) hot water in a pot that’s on the fire (or an electric heating source) or a pot that was just removed from the fire. <ref>Chazon Ovadyah (pg 136) </ref>
# The minhag is to wash the utensils in cold water after performing Hagalah. <ref>Kitzur S”A 116:17</ref>
# If a utensil is used over the fire a majority of its uses such as the oven racks it is cleansed through making it red hot. <Ref>Chazon Ovadyah (pg 124) </ref>
# Grills and skewers need Libun since it probably touched meat that was mixed with Chametz and should be heated until it sparks. <Ref>Chazon Ovadyah (pg 126) </ref>
# An electric or gas oven should be cleaned from all specks of Chametz and left 24 hours unused. If it has a self-cleaning mode, it should be put on self-clean and that is sufficient.<ref>Rabbi Jachter (Gray Matter vol. 2, p. 221) quoting Rabbi Elazar Teitz, [http://www.crcweb.org/Passover/2016/Pesach_Guide_2016.pdf CRC Pesach Guide 2016 (p. 19)], Yesodei Yeshurun v. 6 p. 156-160, OU Pesach Guide 2016 p. 24.</ref> However, if it doesn't have self-clean, many hold that the oven can be heated to the highest temperature it reaches for one hour or two and that is sufficient. <Ref>Rav Ovadia Yosef (Chazon Ovadyah pg 73, Sh”t Yechave Daat 2:63), Rav Aharon Kotler (quoted by Rabbi Eider in Halachos of Pesach 1:180), and Rav Soloveitchik (quoted by Gray Matter vol. 2, p. 219) hold that conventional ovens which don't have a self-cleaning setting can be koshered by raising them to the highest temperature that they can reach for an hour or two.
* Rav Ovadia Yosef explains that according to many rishonim chametz is considered something which is permitted that was absorbed in a utensil that only becomes forbidden over time and as such even items which normally would require libun can suffice with hagalah. Even though Shulchan Aruch O.C. 451:4 holds like the rishonim who hold that chametz is considered like a forbdiden taste all year since on Pesach it will be forbidden and as such libun is necessary on utensils used over the fire, nonetheless, for utensils which can't be koshered any other way and it is difficult not to use the oven all of Pesach, one can rely on the lenient opinion. See Rav Ovadia's responsa for his lengthy explanation.
* Rabbi Soloveitchik offered another reason to be lenient. Since chametz only got absorbed through a certain temperature, those absorptions can be removed in the same way that they went in, which is certainly less than the maximum temperature that the oven can reach. This seems to be at odds with the Pri Megadim E"A 451:30 who holds that libun needs to be a certain temperature to burn out the forbidden tastes, but it is supported by the Arugot Bosem 119. Igrot Moshe YD 1:60 s.v. aval and Or Letzion 3:10:2 agree with Pri Megadim.
* [http://www.crcweb.org/Passover/2016/Pesach_Guide_2016.pdf CRC Pesach Guide 2016 (p. 19)] writes that for non-self cleaning ovens one should heat it to the highest temperature it could reach for one hour after waiting 24 hours. Additionally, the racks and grates should be covered with aluminum foil perforated for air circulation and no food should touch the side bottom or top of the oven on Pesach.* Rav Aharon Felder (Yesodei Yeshurun v. 6 p. 158) writes that even though the oven walls only absorb taste through steam since we're concerned that they absorb taste from something solid spilling on it, it needs libun. Ashkenazim can't follow the majority of uses (Rama 451:6). However, the Or Letzion is concerned even though the absorption is through steam. One proof of the Or Letzion is Shulchan Aruch 451:15 which is a cover of chametz foods on the fire requires libun. One of the reasons of the Tur and Magen Avraham 451:30 because of the steam and the same is relevant to ovens.
</ref> Some hold that ovens which don't have a self-clean setting can 't be koshered for Pesach.<ref>Rav Jachter (Gray Matter vol. 2, p. 218) and OU Pesach Guide 2016 p. 26 quoting Rav Mohe Feinstein</ref> In practice, one should consult one's rabbi.# Racks of electric ovens should be cleansed with Libun and if one does it with Hagalah one has to what to rely on. <Ref>Chazon Ovadyah (pg 132-4) </ref>
* Kaf HaChaim 451:233 notes that wooden tables which one always eats on with a tablecloth don’t need to be kashered and one should simply remove the actual chametz and wipe down the surface. Rav Mordechai Willig (“Shiur 64 – Pesachim” min 80-82) says that strictly speaking this is also true for countertops on which people don’t put chametz directly. Rav Hershel Schachter [http://www.ou.org/community_services/video/67558 (OU Pre-Pesach Webcast 5769, min 11-13)] adds that one could either kasher the counters or cover them, but if one isn’t going to put any hot food on the counters on [[Pesach]] one could simply clean the counters well.
* Thus, Rav Moshe Feinstein (quoted by Halachos of [[Pesach]] p. 140) maintains that one should not kasher Formica countertops, which are made out of hardened plastic, rather these should be washed and covered.</ref>
# Frying pans which one uses with a little oil should be
cleansed with Libun but one has what to rely on to cleanse it with Hagalah. <Ref>Yechave Daat 1:7 Chazon Ovadyah (pg 134) </ref># Pans used to bake cakes with a little oil should not be used on [[Pesach]] because doing Libun on it will break it and one has what to rely on to do Hagalah. <Ref>Yechave Daat 1:7, Yalkut Yosef (Kitzur S”A 451:13) </ref>
# If a liquid mixture absorbed chametz and it was nullified one in sixty it is still forbidden since chametz makes something forbidden in any amount. Even if a bit of that mixture then mixes into another liquid mixture that second mixture is completely forbidden.<ref>Taz YD 92:16 explains that even though we generally don't have two mixtures made forbidden in any amount (תרי משהוין לא אמרינן) for liquid mixtures even the second one is forbidden since part of the first mixture is mixed into the second one. Nekudat Hakesef agrees. Mishna Brurah 467:38 codifies this.</ref>
# If a food absorbed a taste of chametz on Pesach and there was sixty times the volume of the chametz in the permitted food, the whole piece is forbidden. If that piece was cooked with other pieces, according to some poskim, if there's sixty times that original piece it wouldn't render them forbidden. According to most other poskim all of them are forbidden.<ref>Taz 92:16 is lenient since the first piece was only forbidden in a minuscule amount it wouldn't render the cooked mixture forbidden (תרי משהוין לא אמרינן). Dirshu quotes two reasons for the Taz. Either the minuscule amount in the first piece physically can't come out (Rabbi Akiva Eiger 92:3, Pri Megadim YD 92:16) or there's halachically not enough strength in a minuscule amount to forbid the second mixture (Yad Yehuda 92:17, Chazon Ish 34:1). Shach in Nenukdat Hakesef YD 92 argues. Birkei Yosef 447:1 and Mekor Chaim 447:17 are strict.</ref>
===Chametz on Erev Pesach===
# Chametz on the Erev Pesach if it is a solid mixture it is nullified one in two and if it is a liquid mixture it is nullified one in sixty.<ref>Shulchan Aruch 447:2, Mishna Brurah 447:93. However, Shach YD 92 in Nekudat Hakesef argues that chametz on Erev Pesach isn't nullified at all since it is a dvar sheyesh lo matirin like the Rambam.</ref>