When, as a result of any inspection not generated by a tenant complaint, a landlord receives a violation notice citing a serious defect, then the landlord cannot increase the rental fee for those premises until the defects are corrected and the notice abated. If the serious defects cited in the notice are repaired and the notice abated within 30 days from the date of the expiration of the notice, then the increase in the rental fee shall be deemed to begin, and be fully and finally effective for the balance of the term of the lease, from and after the date of the abatement or at the time of the lease renewal, whichever time comes later. If the defects are less than serious, then they must be repaired within 60 days from the date of the expiration of the notice. If less than serious defects are not repaired within the 60-day period, then the rental fee shall revert to the fee charged at the time of the violation notice. If the defects are not repaired within the 30-day period for serious defects or the 60-day period for less than serious defects, then the landlord shall be prohibited from increasing the rental fee until 6 months after the date of abatement. When the landlord receives notice of exterior violations between October 1 and April 1 for repairs which require an air temperature of 50^° F or above, for these defects only the above 60-day period shall be deemed to expire on June 1. City Code, 1976/83, art. 13, §57(b) Ord. 81-280