N.Y.C. Admin. Code § 27-2033: § 27-2033 Access to boiler room.

a. The owner of every multiple dwelling shall have the area, where the building's heating system is located, readily accessible to members of the department to make inspection pursuant to this chapter. In the event such area is kept under lock, a key shall be kept on the premises at all times with such person as the owner shall designate; however, if there is a person residing on the premises who performs janitorial services, such person shall hold the key. The owner shall post a notice in a form approved by the department naming such designated person and his or her location.

b. Multiple dwellings owned and operated by the New York city housing authority shall be exempt from the requirements of this section.