The question of opening refrigerator doors on Shabbat has been a matter of debate for many decades. In this essay we will outline the various approaches taken by the eminent Halachic authorities on this issue. We will discuss the situation in which the refrigerator light has been extinguished and thus does not pose a Halachic challenge. Our focus will be the concern that opening the refrigerator door causes the motor (known as a compressor) to start earlier than it would have, had the door remained closed. Opening the refrigerator door allows warm air to enter, thereby causing a rise in temperature which will inevitably cause the motor to go on sooner.
It is important at the outset to delineate which specific Halachic issues we are concerned with, and whether the issue involves violating a Torah or rabbinic level prohibition. Rav Shlomo Zalman Auerbach, in an incredibly brilliant responsum (Teshuvot Minchat Shlomo 1:10) distinguished by incisive Halachic insights and mastery of the mechanics of how a refrigerator operates, demonstrates that the possible concern is of violating a rabbinic prohibition and not a biblical transgression.
He notes that, in most refrigerators, metal is not heated until it glows. He explains that even though there are gases that are heated in the refrigeration cycle, heating these gases does not constitute an act of Bishul (cooking). Among his reasons are that the gases are not heated by a fire source (see Rambam's Commentary to the Mishna, Shabbat 4:1) and that heating a gaseous substance does not constitute Bishul.
Rav Shlomo Zalman continues to explain that even those (see Chazon Ish Orach Chaim 50:9) who rule that completing an electric circuit which powers an appliance constitutes a Biblical prohibition of Boneh (building) or Makeh B'patish (completing an item) would concede that causing the refrigerator motor to go on earlier does not violate these prohibitions. This is because Boneh or Makeh B'patish is violated only when turning on the electric appliance. The Chazon Ish (see letter published in Minchat Shlomo no. 11) explains that turning on an electric appliance constitutes Boneh because one brings the appliance "from death to life." However, once the refrigerator is plugged in, the action cannot be described as bringing it from death to life by making the motor go on earlier.
Moreover, since the motor will turn off by itself shortly after it goes on, only a rabbinic prohibition is violated. An action is biblically forbidden only if the resulting product is a lasting one (Shel Kayama). Thus, the only possible prohibition involved in causing the motor to go on earlier is the rabbinic prohibition to cause a current flow (see Teshuvot Beit Yitzchak 2:31). Accordingly, the issue of opening a refrigerator is a question of whether a rabbinic prohibition is violated, not a biblical prohibition. Therefore, the possibility of a lenient ruling is considerably greater since there is no concern in this situation of violating a biblical prohibition.
Opening the Refrigerator Door While the Motor is Running
Rav Shlomo Zalman Auerbach argues that opening the refrigerator while the motor is running is unquestionably permissible despite the fact that the motor will remain on longer because the refrigerator door was opened. He reasons that opening the door merely preserves the status quo. It is analogous to the Halacha (Shulchan Aruch O.C. 277:2), that one may close the door that is opposite a fire. This is not considered extinguishing because in the words of the Mishnah Brurah (277:11) "even though the wind would have magnified the fire [had the door remained open] one does not violate the Melachah (forbidden category of labor) of Mechabeh (extinguishing a fire) since he did not perform any action, and if the fire will become extinguished as a result it, is of no concern to us." The Shulchan Aruch HaRav (277:1) explains that this action is not considered even an indirect one (Grama), since he merely prevented the introduction of an impediment to maintaining the status quo (Mene’at Monei’a). Similarly, opening the refrigerator door while the motor is running, merely removes an impediment to the motor continuing to run. Almost all Poskim believe that it is permissible to open the refrigerator door while the motor is running (Teshuvot Har Zvi O.C. 1:151, Teshuvot Igrot Moshe O.C. 2:68, and Teshuvot Yabia Omer 1: O.C. 21).
Opening the Door When the Motor is not Running - Rav Shlomo Zalman's Approach
The question of opening the door when the motor is not running, however, has engendered much debate. Rav Shlomo Zalman Auerbach rules that it is entirely permissible to do so. In fact, he writes that it is not right to be strict on this matter, as it will limit his Oneg Shabbat, enjoyment of Shabbat.
The lenient ruling is based on the fact that opening up the door will not immediately cause the motor to turn on. The inevitable time delay between the opening of the door and causing the motor to go on leads Rav Shlomo Zalman to classify this as a "Grama" - "Koach Sheini" (indirect action, secondary reaction). It is analogous to the following classic case discussed in the Gemara (Sanhedrin 77b). An individual ties up another in front of a powerful stream of water stopped by a dam and releases the dam and thereby kills the victim. If the water killed the person immediately (see Rashi s.v. Girei), then the perpetrator is to be punished with death because he killed directly (Koach Rishon). However, if the water didn't kill him immediately (i.e. there was a significant time delay between the action of releasing the dam and the rushing waters killing the victim), the perpetrator is not subject to the death penalty because he has killed indirectly (Koach Sheini). Similarly, the opening of the doors and allowing the warm air to flow into the refrigerator will take at least a few seconds before it will affect the motor and cause it to go on.
Grama alone is insufficient reason to permit an activity, since the Rama (O.C. 334:22 and see Biur Halacha ad. locum. s.v. DeGram Kibui) rules that Grama is permitted only in situations of great need. Rav Shlomo Zalman asserts, however, that since one's intention is merely to open the door and not to turn on the refrigerator's motor, Grama would be permissible in all situations even absent any unconventional needs. Moreover, he writes that since he is only causing the motor to go on earlier than it would have gone on without his opening the refrigerator door, (also see Teshuvot Minchat Shlomo 1:91:10) one may treat the act of opening of the door even more leniently than Grama. Thus, opening the refrigerator door would be permissible in all situations. Rav Zalman Nechemia Goldberg (a leading Halachic authority who is the son-in-law of Rav Auerbach) told me that it is not necessary to close the refrigerator door as soon as possible after opening it according to the approach of Rav Shlomo Zalman. The reasoning behind the lenient approach applies even if one does not rush to close the door soon after it is opened.
Opening the Refrigerator Door when the Motor is not Running- The Strict Approach
Many Poskim concur with Rav Shlomo Zalman's lenient approach. Indeed, Rav Aharon Lichtenstein told me that Rav Yosef Dov Soloveitchik agreed with the lenient approach. Rav Moshe Feinstein (Teshuvot Igrot Moshe O.C IV: 74- Bishul -28) seems to fully accept Rav Shlomo Zalman's ruling (also see Teshuvot Igrot Moshe O.C. 2:68), as does Rav Eliezer Waldenburg (Tzitz Eliezer 8:12 and 12:92). Encyclopedia Talmudit 18:663 note 13 lists other authorities who subscribe to the lenient approach.
Many eminent authorities, on the other hand, either rule strictly (Teshuvot Har Zvi O.C. 1:151, Teshuvot Chelkat Yaakov 3:179, and Teshuvot Minchat Yitzchak 2:16) or at the least recommend that one to be strict if possible (Rav Yosef Henkin, Eidut LeYisrael p. 122 and Rav Ovadia Yosef, Teshuvot Yabia Omer 1:O.C. 27). The problem is that once an action is performed routinely it cannot be classified merely as Grama (see Shabbat 120b and Rabbeinu Chananeil ad. loc. s.v. Rav Ashi and Bava Kama 60a and Rosh Bava Kama 6:11). Rav Shlomo Zalman responds that this applies only when one intends to create the resultant action. When opening the door one does not intend to turn on the motor.
Conclusion – Caution Necessary
Common practice is to be lenient on this practice, although some people adopt the strict approach. In fact, the Shemirat Shabbat Kehilchata (10:12) counsels one who wishes to be strict to set the refrigerator on a timer, so that the motor shuts off entirely at certain times and to open the refrigerator only during those times.
The Shemirat Shabbat Kehilchata (10:14) cautions that all opinions agree that it is forbidden to open a refrigerator in which a fan goes on when one opens the door and shuts when he closes the door, just as one cannot open a refrigerator if it will cause a light to go on. A remedy to this problem is to tape the switch or otherwise disconnect the fan before Shabbat and Yom Tov. In addition, Rav Shlomo Zalman cautions that his lenient ruling applies only to a refrigerator that works on a compressor system and not to refrigerators that have a heating element. This concern is relevant to refrigerators used in many recreational vehicles which are gas powered. Rav Shlomo Zalman also expresses concern regarding the defrosting systems of refrigerators. Some models have incorporated an adaptive defrost feature which is triggered by the opening of the refrigerator door. Moreover, more expensive models have features such as sensors and illuminated digital readouts that introduce Halachic complications. Accordingly, one must exercise caution when purchasing a refrigerator that it not be source of Halachic problems for use on Shabbat and Yom Tov. For further discussion and guidance regarding potential Halachic problems with certain models as well as potential solutions, see the essay in Kashrus Kurrents available at www.star-k.org/kashrus/kk-cooling-keepcool.htm.
A primary basis of the lenient opinion is that no biblical prohibition is involved in the opening of a refrigerator door. However, opening an oven door is potentially a more severe issue because opening the door causes cool air to enter the oven causing the fire to go on - a Biblical prohibition- unlike the question of opening a refrigerator door on Shabbat.
Accordingly, Rav Moshe Heinemann (cited in the above referenced Kashrus Kurrents essay) rules that one should not open the door to a lit oven unless he opens the door one time in order to remove the food so that the burning to follow is unintended (Davar SheEno Mitkavein), unwanted (Psik Reisha D’lo Nicha Lei), and serves no purpose (Melacha SheEnah Tzricha LeGufa). On the other hand, Rav Dovid Ribiat (The 39 Melochos p.1220) notes (based on a ruling of Rav Moshe Feinstein, published in both Teshuvot Igrot Moshe O.C. 4:74: - Bishul - 28 and in the end of volume two of Rav Shimon Eider’s Halachos of Shabbos) that “most ovens will not automatically ignite when the door is opened” and that it is permissible to open the doors to these ovens on Shabbat. He cites (footnote 86 ad. loc.) an expert who reports “in general the thermostats in ovens are not that sensitive to the extent that they would quickly change due to a change in temperature.” One should consult his Rav for guidance regarding this issue.