How a Furnace Works

Component Glossary

• The Furnace
  

  Fuel and air are combined and ignited by the burners in your furnace. The resulting flame heats a heat exchanger, a series of metal tubes that stay hot for a long time. Air from your home is warmed when it’s blown across the heat exchanger, and the furnace’s blower distributes this warm air throughout your house through the ductwork.

• Return Register
  

  The return register is where the air enters your furnace & air conditioning system. It is very important to keep any item from blocking the incoming air.

• Gas Shutoff Valve
  

  The gas shut off valve is a safety valve that will shut off all gas to your furnace. The gas shut off should always remain wide open unless unit is being serviced or if disaster strikes. The gas valve is checked during routine maintenance checks.

• Draft Hood
  

  A draft hood is the area in the front at the top of the furnace where the hot gas fumes enter the flue pipe. On newer furnaces this area has a draft motor which forces the air up the flue.

• Power Switch
  

  The power switch is for servicing equipment. It is usually located above the furnace (looks like a light switch) or on the wall near by a furnace. If your furnace is old, or close to the breaker box, you may not have one.

• Flame Sensor
  

  The flame sensor is the most delicate part of the entire furnace, it is easily broken and needs cleaned on a regular basis. The flame sensor is cleaned during yearly maintenance checks.

• Burners
  

  The burners are where gas & oxygen come together with an ignition source and create heat. These are regularly cleaned during yearly maintenance checks. Dirty burners can cause Carbon Monoxide and flame rollout dangers.

• Filter
  

  The filter removes particles of dirt, dust, dander, etc. out of the air. Many different types exist and it is critical that this is cleaned and/or replaced every 30-60 days. Between the options of filters & air cleaners, you can clean 1%-99.98% of dirt, dust, dander out of the air. If your house suffers from dust, explore this option more.

• Supply Register
  

  The supply air register is where the conditioned air exits your furnace and air conditioning system. If at all possible, keep most registers completely open. It is very important for your system to breathe properly.

• Heat Exchanger
  

  The heat exchanger is the thin metal tubing that your hot gas is in and the cool air flows on the outside heating up as it gets closer to top of furnace. Heat exchangers get cracks in them over time and will cause the need to replace the furnace. Do NOT run a furnace with a cracked heat exchanger. Heat exchangers are checked during yealy maintenance checks.

• Combustion Chamber
  

  The combustion chamber is the area between the burners and the heat exchanger that all heat is generated in. It is very important to keep this area cleaned and air flow properly flowing to and from. The combustion chamber is regularly cleaned during yearly maintenance checks.

• Gas Control Valve
  

  The gas control valve is a component of your furnace’s fuel system that opens and closes to allow the flow of gas to the pilot light and burners.

• Blower Motor
  

  The blower motor circulates the air throughout your furnace and air conditioning system all year long. Using a high efficiency motor instead of a standard efficiency motor can save you up to 60% on electric usage. Keeping the filter properly maintained is critical to the life expectancy of a blower motor. The blower motor is regularly checked during yearly maintenance checks.