Fuels / Heating / Cooling Hart & Iliff has provided top quality products and services to the residents of Sussex, Northern Morris and Northern Warren Counties since 1889. Our products and services include: 1. Delivery of our exclusive Ultrablend Heating Oil and Ultra Low Sulfur Diesel 2. Installation, repair and maintenance of all types of heating equipment. 3. Installation, repair and maintenance of domestic hot water making equipment, including solar thermal hot water making systems. 4. Installation, repair and maintenance of all types of central air conditioning equipment. 5. Installation, repair and maintenance of ventilation equipment.