1. A person who neglected to search forchametzon the night of the fourteenth of Nissan must conduct the search during the day of the fourteenth. Though it is daylight, he must nevertheless do the inspection with the light of a candle, and not only with the sunlight, in order to properly illuminate the holes and crevices. But if he is inspecting the porch or the like, [and there is no partition whatsoever, not even a glass window], where there is abundant sunlight, he does not need to use a candle there. [This rule, of not needing a candle when inspecting a porch, applies only after the fact; but, in the first place, one is obligated to inspect that area on the night of the fourteenth, by candle.] (Shulchan Aruch and Mishnah Berurah 433).
2. One does not search forchametzwith the light of a torch, which is when two or more wicks/candles are combined. This is because with such a large flame it is impossible to get into holes and crevices and also because the person is afraid of trying to get it into such places for fear that he will cause a fire in the house. Even after the fact, [i.e. the person used a torch of two or more flames combined] the search is invalid and he must do the search again with a single candle (ibid.).
