For all of your home comfort needs, trust the experts at Cullen Heating & Air Conditioning Serving All of Durham Region for over 50 Years. Nominated #1 Heating & Air Conditioning Contractors. We offer customers a range of home comfort appliances including furnaces, air conditioners, heat pumps, humidifiers, ultra violet lights, gas fireplaces, water heaters, tankless water heaters and more. All installations of Furnaces and Air Conditioners come with a 10-year warranty on parts and 10 Year warranty on labour. FREE in home Estimates. Call Us today to book an appointment.