Is one obligated to listen to a Rav? [duplicate]

Question

If I ask my rav for halachic advice, must I follow it or can I ask a different posek?

Seperately, if I ask my rav for personal advice, must I listen?

Answer 1

Avodah Zarah 7a rules:

ת"ר הנשאל לחכם וטימא לא ישאל לחכם ויטהר לחכם ואסר לא ישאל לחכם ויתיר

The Sages taught: One who asks a sage and he declares it impure, he may not ask [another] sage to rule that it's pure. To [ask] a sage who forbids, he may not ask [another] sage who permits.

Tosfos on the spot explain that this is only if one doesn't inform the second sage of the first one's ruling:

וא"ת וכי לא ישאל לכל החכמים וידונו זה עם זה אולי ישיבוהו מדבריו וי"ל דאינו אסור אלא לשואל אם לא יודיע לו כבר שאלתי לפלוני ואסר לי אבל אם אומר לו כבר שאלתי פלוני חכם מותר

If you will say: Why can he not ask all the sages and have them judge with each other; perhaps he will cause him to retract from his words! There is to say: It's only forbidden to ask if he does not inform him, "I already asked so-and-so, and he forbade it to me." But if he says to him, "I already asked so-and-so the sage," it's permissible.

Therefore, it would come out that once one has asked his rav for halachic advice, he can ask another rav for a second opinion, but only if he tells him that the question's already been asked and answered.

However, don't get your hopes up that the second rav will provide a different answer. As Tosfos continue,

אבל ודאי החכם יזהר שלא יתיר כדאמרי' בפרק כל היד (נדה דף כ: ושם ד"ה אגמריה) חכם שאסר אין חבירו רשאי להתיר אא"כ יוכל להחזירו כגון שטעה בדבר משנה או אפילו בשיקול הדעת

But certainly the sage should be careful not to permit [that which the first sage forbade], as we say in the chapter Kol Hayad [in Maseches Niddah], "A sage who forbade - his fellow is not allowed to permit unless he can respond to him, for instance if he made a mistake regarding a Mishnah, or even with equal logic."

(Tosfos continue further citing several other Gemaras to make the same point.)

Answer 2

If I remember correctly, you may go to a second rabbi, provided you inform him of the ruling of the first rabbi you visited.