סימן פ סעיף ב

אָסוּר לִפְתּוֹחַ דֶּלֶת אוֹ חַלּוֹן נֶגֶד נֵר דּוֹלֵק כְּשֶׁהוּא קָרוֹב לָהֶם, שֶׁמָּא יְכַבֶּה עַל יְדֵי זֶה. אֲבָל מֻתָּר לִסְגּוֹר דֶּלֶת וְחַלּוֹן. וּפֶתַח הַתַּנּוּר שֶׁיֶּשׁ בּוֹ אֵשׁ, אָסוּר, בֵּין לִפְתּוֹחַ בֵּין לִסְגּוֹר, כִּי עַל יְדֵי זֶה הוּא מַבְעִיר אוֹ מְכַבֶּה (רעז רגט).

It is forbidden to open a door or window directly opposite and close to⁸For the wind from outside may blow out the candle. Thus it is forbidden even to open the door slowly [Magein Avraham, Eliyahu Rabbah, Chayei Adam, etc]. Where there is no wind blowing, Mishnah Berurah rules that you may be lenient, provided you open the door slowly so as not to create a draft that could blow out the candle. a burning candle lest the flame be extinguished.⁹Maharsha (Maseches Shabbos 120b) states that it is almost certain that the candle will be blown out. But it is permitted to close a door or window [even in such circumstances].¹⁰Even if closing the door removes the source of wind and the fire is extinguished. (Mishnah Berurah) The door of an oven in which a fire is burning¹¹In the case of smoldering coals, opening the oven door is unanimously prohibited, and most poskim agree that closing it is also prohibited. (Mishnah Berurah 259) must not be opened or closed, for by doing so, the fire is either increased or extinguished.¹²This may also apply to modern thermostat controlled gas and electric ovens, where opening and closing the oven door has an almost immediate effect on the intensity of the flame. A competent halachic authority should be consulted.

תנא דבי אליהו כל השונה הלכות בכל יום מובטח לו שהוא בן העולם הבא שנאמר הליכות עולם לו אל תקרי הליכות אלא הלכות (נדה ע"ג.)