Hi. My friends live in an absorption center where there used a burner without Kashering it. The previous users may have Kashered it or maybe they didn’t, as a mixture of religious and non- religious people live in the absorption center, which is in Israel. Do they have to kosher their pans which were placed on the burner etc.. I noticed on the forum in answer to a similar question you said that it wouldn’t be a problem if there is non kosher spillage on a burner but it will be a problem if there is non kosher fat/ residue on the burner.
Shalom, Thank you for your question. One can assume that the stove top burners kosher themselves with the heat of the flame when they are turned on. Because of this, even if they were not koshered before use the pans are still acceptable. Only if the burners were sticky or moist with non kosher fats etc would one have cause for concern. We can assume that the burners were not left in such an unclean state – nor would they have been used in such a state without being first cleaned. Because of this their pans are still kosher. Blessings.