Mechanical systems, both existing and new, and all parts thereof shall be maintained in proper operating condition in accordance with the original design and in a safe and sanitary condition. Any device or safeguard which is required by this chapter shall be maintained in compliance with the provisions under which it was installed. The owner or the owner's designated agent shall be responsible for the maintenance of mechanical systems. To determine compliance with this provision, the Building Commissioner shall have the authority to require a mechanical system to be reinspected.