ABSTRACT
This chapter describes heating units that can be found around the country, how they operate, how to inspect them to identify and note problems, and in some cases, how to make repairs. Because fuel-burning appliances have potential to cause serious problems in the home, it provides a discussion of how to check for these types of problems. Jet burners, which are becoming more common in gas burning furnaces, also use a Venturi effect to mix gas and air, but have only one hole or orifice out of which the mixed air and gas pass before igniting. The heat exchanger is located above the burners in gas- and oil-fired furnaces, and separates the products of combustion from the air to be heated. The fan control is a temperature-sensitive switch, completely independent of the thermostat, that turns the furnace blower on and off at preset temperatures. The chapter also describes cooling units, how they operate and how to inspect and repair them.
