No dwelling may be inhabited unless the provisions of this subchapter are met. Unless otherwise indicated, the property owners are responsible for taking or causing to be taken any action necessary to maintain compliance with the provisions set forth hereafter. Every dwelling shall have heating equipment and appurtenances which are properly installed, maintained in safe and good working condition, and capable of safely and adequately heating all habitable rooms and bathrooms to a temperature of at least 68°F. measured at a distance 36 inches above floor level under ordinary winter conditions.