Brewing a porter, pitched my yeast and started with a 1.056. My air conditioner broke for 1 day and the beer got to about 80 degrees after about 1 1/2 weeks of fermentation. Beer has been sitting at 1.036 for two weeks now. Can I repitch? Or is it needing to be dumped? And if I can repitch, does it need to be transferred to a new bucket first?
There's no reason to dump a beer that isn't contaminated. After 1.5 weeks and a trip to 80F, the beer should be done fermenting. And warm temps late in fermentation have little impact on flavor.
You can try stirring up the yeast, but a re-pitch of active yeast is probably worth doing. If you can make a starter that would really help, since the partly fermented beer contains no oxygen.
Transferring is unnecessary, and risky with the residual sugar still present.
No matter what the gravity reads, that beer is done. What was the OG? Was it an extract batch? I doubt repitching will make any difference.
I would start by just swirling the carboy so that the yeast bed breaks up. Leave it for a few days and take another reading. It there is no or little change, then do as Pepi says; make a starter and re-pitch to the same fermenter.
I'd pop the lid to let in some air, then reattach the lid and give fermenter a good shake, to stir things up, wait a day to see if it kicks off again, if not as pepi suggests use a starter.