A furnace brings warm air to both residential and commercial buildings throughout the winter season. However, most people never thought too much about how a furnace makes heat and its components. Knowing the parts of a furnace better helps you to understand how a furnace works and even better, troubleshooting problems as they develop. Air Supply Heating & Air Conditioning would like to share the components of the furnace and what they do.

Main Components of a Furnace

Pilot Light – Older furnace units have a pilot light that burns continuously and is ready to ignite the gas when the furnace turns on or starts a heating cycle. Many furnace start up failures is due to a dirty or faulty pilot light.
Thermocouple – A thermocouple is designed to detect a lit pilot light. If the pilot light is lit, the thermocouple will send a signal to the gas valve to open and allow gas to flow. The thermocouple can become dirty or bumped out of place and will prevent the gas valve from opening.
Hot Surface Ignitor – New model furnaces use a hot surface ignitor instead of a pilot light. Electrical currents pass through the ignitor which creates heat to start the combustion once the gas valve is open or on.
Flame Sensor – A flame sensor is part of the furnace safety system. The flame sensor is designed to detect heat from the hot surface ignitor. If the flame senor doesn’t detect heat from the hot surface ignitor, the sensor will turn off the gas supply. Sometimes when the furnace fails to start a heating cycle, the flame sensor is dirty or broken.
Gas Valve – The gas valve controls the amount of gas that flows to the furnace. Within the electrical system there are a number of valves that open and close to ensure gas doesn’t continuously flow. Occasionally, the gas valve can fail and prevent gas to flow to the furnace.
Burners – The burners mixes the gas with air to create a flame. The flame becomes the primary heating source for the furnace. Burners can corrode or wear down and need to be replaced.
Heat Exchanger – A heat exchanger, also known as the combustion chamber, houses all of the toxic gases that develop when burning the fuel. The heat exchanger vents the toxic gas outside and away from the home. The heat exchanger gets very hot and cools down rapidly. This can cause stress and lead to cracks.
Draft Inducer Motor – The draft inducer helps pump or vacuum the toxic gases before the furnace starts, to ensure as soon and the fuel is burned that the fumes are exhausted out.
Pressure Switch – The pressure switch is part of the draft inducer and switches the motor on and off. If the pressure switch vacuum suction from the inducer isn’t working, the pressure switch will stop the gas from flowing to the furnace.
Blower Motor and Capacitor – The blower motor and fan circulate the warm air from the furnace and throughout the home. The capacitor is the blower controller that turns the blower on and off.
Limit Switch – The limit switch is designed to detect temperature within the furnace. If the furnace ever runs too hot, the limit switch turns off the gas or fuel to the furnace to prevent damage to the furnace or a hazardous situation.

Central Forced Air Furnace Heating Diagnosis, Repair, Replacement, Maintenance & More in Summerlin, North LV, Henderson, Centennial, Enterprise, Lone Mountain Village, Paradise, Sunrise Manor, Spring Valley, Aliante, Desert Shores, Eldorado, Peccole Ranch, Silverado Ranch, Tuscany Village, Whitney, Winchester & Las Vegas Nevada

If one of the major components of the furnace develops a problem, the entire furnace will be affected. If you are having heating problems and need HVAC services, contact Air Supply Heating & Air Conditioning.