There are many parts to a Rheem furnace, but the most integral parts are the gas valve, the pilot burner and the thermocouple. The flame sensor rod, spark ignition and hot surface ignition are also important parts.
On Rheem furnaces, the gas valve serves as the gateway for gas when a thermostat is directed to change temperature. If heat is needed and an individual manually raises the temperature on the thermostat, the gas valve, which is usually electronically connected, opens and allows gas to shuttle through the furnace.
When the gas valve is set on "Pilot" or the manual setting for lighting, the pilot burner regulates the direction of the flame inside the furnace. Pilot burners guide the pathway of the pilot flame into the main site of burning. This allows the main burner ignition to respond properly to changes in heat setting.
The thermocouple functions as the sensor for these changes in heat setting. By recognizing the difference in temperature of two semiconductors, the thermocouple tells the main unit of temperature changes via a voltage signal. Again, giving information to the main unit, the flame sensor rod alerts the burner if the ignitions have succeeded in igniting a flame.
Some Rheem furnaces have a spark ignition, while others use a less expensive hot surface ignition. The spark ignition is the site of spark plug and is responsible for creating combustion through an air-fuel mixture. The hot surface ignition utilizes a electric current and hot surface by means of ignition.