In what areas is one obligated to perform the Bedika?
All the areas that are obligated to be cleaned, as explained in the previous chapter, are required to be checked for Chametz at night with the use of a candle [or flashlight and the like]. This applies even if one has completely cleaned and checked that area by day. [Accordingly, all the areas that were already cleaned for Pesach must be rechecked at night with a Bedika using candlelight [or flashlight]. However, some Poskim rule that once the area has been properly cleaned, even during the day, it no longer needs to be checked at all, and so is the custom of many. Other Poskim rule that all moveable items merely require a swift glance at night, and not a thorough checking. Practically, it is best to be stringent like the former approach which requires a Bedika at night to even cleaned areas, and so was the directive of the Rebbe Rashab. This Bedika is valid on any night, even prior to the 14th. Accordingly, the following advice should be used to lessen the burden of rechecking everything on the night of the 14th: After cleaning an individual item, such as a drawer, shelf, cabinet, fridge, room, and the like, one is to check the item that night using a flash light or light bulb, and intend to perform the Bedika on it at this time. For example, if one cleaned the fridge on the 10th of Nissan, he should check it that night with a flashlight/room light, and only then line it. A blessing is not recited on this Bedika. In all cases, for the Bedika to remain valid, one is to make sure that Chametz is guarded from that area from here onwards. Likewise, one is to leave at least one area unchecked, which he will check with a blessing on the night of the 14th.]
All areas that require cleaning for Chametz, likewise require a Bedika with candle light [or flash light] at night to verify their cleanliness. In order to lessen the burden of requiring a rechecking of the entire home and its belongings on the night of the 14th, one can intend to check the room/item the same night that it was cleaned, even several days before the night of the 14th, and thus fulfill his Mitzvah of Bedika without needing to recheck it later on. Nonetheless, many are lenient to not recheck at night any area or furniture that was thoroughly scrubbed and cleaned from Chametz.
The Bedika of the Rebbe Rashab on an already cleaned area:
Rav Yaakov Landau related the following incident that occurred to him in the home of the Rebbe Rashab, regarding Bedikas Chametz to precleaned areas: One time the Rabbanis, Shterna Sarah z”l, told me that we need to do a Bedika to the room that was cleaned for use for the Pesach products. This was on the night of Rosh Chodesh Nissan. That room was fully cleaned and “Kashered”, and many of the Pesach products were already stored inside it, such as the wine and other items. It was discovered that the walls were not properly cleaned and therefore the Rebbe Rashab instructed that everything be removed and the walls re-cleaned. After this repeated cleaning the Rebbetzin said that the room needs to have a Bedika done to it. I entered the room of the Rebbe Rashab to receive clarification regarding the necessity for this Bedika after the room was clearly cleaned of all Chametz. The Rebbe Rashab replied: “In general, when people clean a room for Chametz, in majority of cases they forget completely to do a Bedika afterwards. Even if they do check it, it is a very swift check, which is most certainly invalid, as all the items are already in the room. Therefore, the room should have a Bedika performed in it without a blessing the same night that it is cleaned for Pesach.”
The Bedikah of the Alter Rebbe:
The Alter Rebbe went to Mezritch for the first time in the year 1764 and remained there until a few days before Pesach of 1765. Upon returning home, on the 13th of Nissan that year he did not eat due to his preoccupation with the preparations for Bedikas Chametz, assuring that all the Divine intents that he learned in Mezritch regarding the Bedikah would be translated into action. The actual Bedikah continued throughout the entire night despite the fact that he only had one room in his possession.
 See there that all areas which one remembers entering Chametz into, even once, or that it is common to enter while eating, require checking.
 Admur 431/5 that the Takana for Bedika is on the night of the 14th; 433/7 that one can check it any night without a blessing, even prior to the 14th; 433/5-6 that the Bedika is invalid during the day and is only valid at night; 433/38 that all areas that require Bedika are to be swept clean before the Bedika; Accordingly, for a joint of all the above rulings we conclude that all cleaned areas must be checked for Chametz at night with a candle.
 Admur 433/39 that sweeping does not suffice and 433/6 that checking by day does not suffice; Michaber 433/11; Rama 433/11 that all areas must be cleaned before the Bedika; M”A 433/20 “Some are accustomed to after the cleaning to only do a Bedika to some of the rooms, this is improper”; M”B 433/45 [however in Shaar Hatziyon 432/12 he rules differently]; Directive of Rebbe Rashab to Rav Yaakov Landau; Sefer Hakashrus 6/10 footnote 38; Nitei Gavriel p. 135; 136; 161, brought also in Piskeiy Teshuvos 433/8
 Directive of Rebbe Rashab to Rav Yaakov Landau; Hiskashrus Pesach; Sefer Hakashrus 6/10 footnote 38; Nitei Gavriel p. 135; 136; 161, brought also in Piskeiy Teshuvos 433/8
 Piskeiy Teshuvah 432/2 in name of Eimek Halacha 143, brought in Shaar Hatziyon 432/12 that today that we thoroughly clean all the areas before the night of the 14th they are exempt from Bedika; Shaareiy Teshuva end of 433 “Today the masses are lenient to not to properly check the home within every area, as it was already properly cleaned beforehand; Chachmas Shlomo 433/11 “If one cleaned the area at least three days before the night of the 14th, he is not required to do a Bedika at night to the area as it has a Chazaka that it is free of Chametz, and is no different than an area in which one never entered Chametz into to begin with”; Nitei Gavriel Pesach 1/76
 Daas Torah 433
 Rebbe Rashab ibid; Nitei Gavriel p. 135; 136; 161 writes that if possible one should search all areas at night with a candle, even those areas which already have been cleaned, and they thus are to be checked before they are covered with paper and the like. Thus, it seems that he learned that one should suspect for the view that the Takana to check at night applies to all items, even those previously cleaned. [However, earlier on page 78 he contradicts himself and rules that if one has already cleaned all areas before Bedika then he must from the letter of the law place out the ten pieces of bread. Vetzaruch Iyun] Piskeiy Teshuvos 433/8 records this opinion; Sefer Hakashrus writes that when cleaning the kitchen closets one must remember to check it with a candle, and that it is unfathomable that the area which most has Chametz will not be checked as is required; So I received from several Rabbanei Anash, that even cleaned areas must be checked.
 Admur 433/7
 Directive of Rebbe Rashab to Rav Yaakov Landau, in story ibid; So I received from several Rabbanei Anash, that they themselves are accustomed to do so in order to lessen the burden of needing to recheck everything on the night of the 14th. [Heard from Rav S.Z. Labkowski as well as many other Rabbanim that so they do in their own home.]
 Admur 433/7
 Admur ibid
 Admur ibid
 Yagdil Torah N.Y. 52 p. 150