The Halachic authorities address the question of whether the Beracha of "She’hehiyanu" should be recited before one performs "Bedikat Hametz" – the search for Hametz on the night before Pesach. Generally, we recite this Beracha when we perform an infrequent Misva, and thus, seemingly, it should be recited before "Bedikat Hametz," which we perform just once a year.
However, the Rosh (Rabbenu Asher Ben Yehiel, Germany-Spain, 1250-1327), in one of his responsa (25), writes (listen to audio recording for precise citation) that "She’hehiyanu" is not recited before the search for Hametz, because this Misva is covered by the "She’hehiyanu" recitation at the Seder. The search for Hametz is done for the purpose of the Pesach celebration, and thus the Beracha of "She’hehiyanu" we recite over the Yom Tob at Kiddush covers also the "Bedikat Hametz." A different theory is presented by Rabbenu Peretz (Rav Peretz Ben Eliyahu of Corbeil, d. 1295), who explains (listen to audio recording for precise citation) that since the Misva is to destroy all the Hametz in our possession, and we might feel some distress over having to destroy our food, the recitation of the joyous Beracha of "She’hehiyanu" is not appropriate.
Although the Peri Hadash (Rav Hizkiya Da Silva, 1659-1698) ruled that one should recite "She’hehiyanu" before the search for Hametz, the consensus among the Halachic authorities does not follow this opinion. Indeed, the Hid"a (Rav Haim Yosef David Azulai, 1724-1806) observed that the widespread practice is not to recite "She’hehiyanu" before "Bedikat Hametz." However, the Ben Ish Hai (Rav Yosef Haim of Baghdad, 1833-1909) writes that if one has a new garment or a new fruit, he should recite "She’hehiyanu" over the new garment or fruit and have in mind that the Beracha should cover the search for Hametz, as well.
Before beginning the search, one recites the Beracha, "Baruch Ata…Asher Kideshanu…Al Bi’ur Hametz." It is proper not to speak about matters unrelated to the search from the moment one recites the Beracha until he completes the search. Strictly speaking, however, it is forbidden to speak only until one begins searching. If one did speak about matters unrelated to the search after reciting the Beracha and before he began searching, he must repeat the Beracha.
If one needs to check for Hametz several different locations – such as his house and his office – he should have in mind when reciting the Beracha that it should refer to the search in all the locations, and then he does not recite a new Beracha at each location.
Summary: Before beginning "Bedikat Hametz," one recites the Beracha of "Al Bi’ur Hametz," but not the Beracha of "She’hehiyanu." After reciting the Beracha, one should not speak about matters unrelated to the search until the search is completed. If one spoke about unrelated matters after reciting the Beracha and before beginning the search, he must repeat the Beracha.
