Q. Dear Rabbi, Can I use a timer for Shabbos to turn on a coffeemaker, hot water urn or a crock pot? What about Yom Tov? Can I set the timer to turn on the second day of Yom Tov so I can cook a Chulent for Shabbos or does the crock pot need to be left on for all 3 days?

A. Many Poiskim (Chazon Ish O.C. 38,2 – Tzitz Eliezer 2, 6- Be’er Moishe pg. 103 – Sheorim Metzuyonim Behalacha 72,37 et.al.), permit to place food before Shabbos on an electric heating device that will turn itself on during Shabbos by means of a timer, also set before Shabbos. However, they prohibit doing so on Shabbos even before the device is turned on. Some permit in need via a Gentile, or after the fact.

If the timer was set before the beginning of Yom Tov, it is permitted to place the uncooked food on it.

Rabbi A. Bartfeld as advised by Horav Shlomo Miller Shlit”a