The Misva of Bedikat Hametz – searching the house for Hametz – must be performed on the night of the 14th of Nissan, which is the night before the night of the Seder. The search should preferably be done immediately at Set Ha’kochavim (nightfall). Those who generally follow the view of Rabbenu Tam regarding Set Ha’kochavim, as occurring 72 minutes after sundown, may nevertheless assume the earlier time of Set Ha’kochavim with regard to Bedikat Hametz. Since Bedikat Hametz was enacted by the Sages, and does not constitute a Torah obligation, one may be lenient in this regard even if one normally ensures to satisfy the view of Rabbenu Tam. Thus, one may begin the search 20 minutes after sundown, or, if one wants to be more stringent, 30 minutes after sundown.
The Hid"a (Rav Haim Yosef David Azulai, 1724-1807), in his work Mahazik Beracha (Se’if Katan 7), and the Sha’areh Teshuba (Se’if Katan 1), observe the widespread practice not to make a thorough search of one’s home for Bedikat Hametz. Generally, the wives clean the home very thoroughly during the days and weeks preceding Pesah, and ensure to keep Hametz away from the rooms that had been cleaned. Given the thorough cleaning that the house had already undergone, people do not bother to conduct a thorough search for Bedikat Hametz, because, understandably, there is no chance of finding Hametz in those areas. The Halachic authorities rule that there is a legitimate Halachic basis for this leniency. Even though the Sages required a formal search with a candle on the night of the 14th of Nissan, the search is required only in "Mekomot She’machnisim Bo Hametz" – places where Hametz is used and there is thus a chance of finding Hametz there. Places in the home that were thoroughly cleaned and kept free of Hametz have the status of places where Hametz is not used at all, and thus do not, technically speaking, require Bedikat Hametz. Thus, although one is certainly required to conduct a search on the night of the 14th of Nissan, there is room to justify the prevalent practice not to search thoroughly in all areas of the home, since the house had already been thoroughly cleaned. (According to some authorities, this is allowed as long as the house was cleaned three days before Pesah, which, of course, is usually the case nowadays.)
People who spend Pesah in a hotel must ensure to rid the room of Hametz food that was left for them by the hotel staff. Even though one did not request or take possession of these snacks, nevertheless, it is forbidden to have these foods in the room during Pesah, given the risk that one might eat them. Therefore, if one checks into a hotel before or during Pesah and sees food in the room that is not kosher for Pesah, he must call the hotel staff and ask that it be removed.
Summary: Bedikat Hametz should be performed immediately at nightfall – 20-30 minutes after sundown – on the night of the 14th of Nissan, which is the night before the night of the Seder. Many people do not search thoroughly, relying on the thorough cleaning performed by their wives in the days and weeks before Pesah, and there is Halachic basis for this leniency. If one checks into a hotel before or during Pesah and sees food that is not kosher for Pesah which was left for him by the hotel, he must call the hotel staff and ask that it be removed.
