Bedikas Chometz in the Weeks Before Pesach
It is permissible to begin – although not complete – the mitzvah of bedikas chametz earlier than the night of the 14th of Nisan. Regardless of the date of the search, it must be conducted during night hours and a candle must be used. In such a case, a blessing is not recited, and care must be taken to avoid introducing any chametz into the searched area following the conclusion of the search until after Pesach. One room must be left unsearched, so that a search can be conducted in that room on the night of the fourteenth, with a blessing.
Here is a practical example of such a scenario: One intends to enter his office during Pesach. In that case, the office cannot be included in the sale of chametz. It must be cleaned and searched instead, but he does not need to wait until the night of the fourteenth; he can search it earlier, as explained above. He must be extremely careful not to introduce chametz to the office following his search.
If one cleans a room from chametz with the intention of storing his Pesach items there, it is wise to wait until the night after he has cleaned it to conduct a search for chametz by either candlelight or the use of an electric flashlight, and not to rely on the search that he will conduct on the night of the fourteenth. He can then introduce his Pesach items.
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