Siman 385
Presented here for study, not as a practical ruling. The Shulchan Aruch rules by Sephardi custom, the Rema's glosses by Ashkenazi custom, and the Kitzur follows Ashkenazi custom. For a practical question, ask your rabbi.
א צְדוֹקִי הֲרֵי הוּא כְּיִשְׂרָאֵל, וּמְבַטֵּל רְשׁוּת. אֲבָל עֵרוּב אֵינוֹ מוֹעִיל כֵּיוָן שֶׁאֵינוֹ מוֹדֶה בְּעֵרוּב.
1 Laws of Sadducee and apostates in eruv. Containing 4 paragraphs. A Sadducee is like a Jew and can nullify his domain, but an eruv is not effective since he does not acknowledge the validity of eruv.
ב כּוּתִי הֲרֵי הוּא כִּשְׁאָר עַמִּים, וְאֵין לוֹ תַּקָּנָה אֶלָּא בִּשְׂכִירוּת.
2 A Samaritan is like other non-Jews, and has no remedy except through rental [of his domain].
ג יִשְׂרָאֵל מוּמָר לַעֲבוֹדַת אֱלִילִים אוֹ לְחַלֵּל שַׁבָּתוֹת בְּפַרְהֶסְיָא, אֲפִלּוּ אֵינוֹ מְחַלְּלוֹ אֶלָּא בְּאִסוּר דְּרַבָּנָן, הֲרֵי הוּא כְּעַכּוּ"ם. וְאִם אֵינוֹ מְחַלֵּל אֶלָּא בְּצִנְעָה, אֲפִלּוּ מְחַלְּלוֹ בְּאִסוּר דְּאוֹרַיְיתָא, הֲרֵי הוּא כְּיִשְׂרָאֵל וּמְבַטֵּל רְשׁוּת.
3 A Jew who has apostatized to idolatry, or who desecrates the Sabbath publicly — even if he violates only a rabbinic prohibition — is like a non-Jew. But if he violates only in private, even a Torah prohibition, he is like a Jew and can nullify his domain.
ד יִשְׂרָאֵל שֶׁהֵמִיר, וְהָיוּ לוֹ בָּתִּים בִּשְׁכוּנַת יִשְׂרָאֵל שֶׁעֵרְבוּ לְכָל הַשָּׁנָה, אִם אֵין לוֹ פֶּתַח אַחֵר כְּלָל הוּא אוֹסֵר בְּכָל שַׁבָּת שֶׁחָל לְאַחַר שֶׁהֵמִיר, אֲבָל אִם יֵשׁ לוֹ פֶּתַח אַחֵר לִשְׁכוּנַת הָעַכּוּ"ם, אֲפִלּוּ הוּא פֶּתַח קָטָן שֶׁלֹּא הָיָה רָגִיל בּוֹ מִתְּחִלָּה, דּוֹחִין אוֹתוֹ אֵצֶל פֶּתַח הַפָּתוּחַ לִשְׁכוּנַת הָעַכּוּ"ם.
4 A Jew who converted [to another religion] and had houses in a Jewish courtyard that made an eruv for the entire year: if he has no other entrance at all, he prohibits [carrying] on every Sabbath that occurs after his conversion. But if he has another entrance to a non-Jewish courtyard — even a small opening that he did not initially use regularly — we push him toward the entrance that opens to the non-Jewish courtyard.