/kloc-Do I have to pay the heating fee for returning the rent in October?

There is no "should". Official website inquiry of Shenyang Tianrun Thermal Power Heating Co., Ltd. shows that the heating period is from 10 to 15 every year to April 15 the following year, which is ***6 months. If the rent is returned before 10, 15, there is no need to pay the heating fee. Heating fee refers to the fee charged to users to keep indoor warm in winter.