heating repairIf you aren’t an HVAC technician, your furnace may seem complicated. There are a lot of different parts and each one has their own function. If one component is not working properly, it can cause issues with the rest of the system. With this in mind, it can be difficult to understand what is wrong when your system isn’t working properly.

B&L Ott in Reading, PA is always here to help you maintain, repair, or replace your furnace when needed. We will answer any questions you may have and help you understand how to better use and maintain your system. To help you begin to gain a better understanding, B&L Ott has compiled this guide to furnace components for you. 

Components of Your Furnace

Blower Motor & Blower Wheel

The blower motor and wheel are responsible for circulating air throughout your home. It takes air in through your return air ducts and transports it through the furnace where it is heated. Once the air is heated, the blower pushes the air back through your air ducts and into your home.

It is very important that the blower wheel stays clean. A dirty wheel is not able to scoop up as much air. This means your furnace loses efficiency. In this case, your utility bills may rise and you may notice uneven heating throughout your home. The best way to ensure your blower wheel stays clean is by changing your filter regularly and by calling B&L Ott for biannual maintenance. If you notice uneven heating in your home, B&L Ott can help. We can balance your duct system to direct the conditioned air where you need it to go or we can help you upgrade your blower motor.

Heat Exchanger

The heat exchanger does what its name implies; it exchanges heat. It has a series of passages for the exhaust from the flame to travel through. As the exhausts travel through these passages, the heat exchanger extracts as much heat as possible, while still directing the exhaust through the vent (chimney or vent piping).

Heat exchangers take a lot of abuse. It expands and contracts as it constantly heats up and cools down all day long. This can cause cracks in the heat exchangers. If too much dirt builds up and restricts the air from passing through, the heat exchanger can also overheat. This makes the problem even worse.

This information is important because a cracked heat exchanger leaks carbon monoxide, a poisonous gas that is both odorless and tasteless. The best way to protect your family from a carbon monoxide leak is to get a carbon monoxide detector and ensure that your system is properly maintained by B&L Ott every single year.

Ignition Assembly

trane furnaceThe ignition assembly is a series of components that work together to safely control the flow of gas.

In a gas or propane furnace these components include:

Gas Valve: The gas valve controls the flow of gas.

Igniter: The igniter ignites the gas to create a flame that will travel into the heat exchanger.  

Flame Sensor: The flame sensor provides safety by sensing when a flame is present. It also communicates with the gas valve. If the flame sensor does not detect a flame, it will close the gas valve.

Safety Switches: Safety switches provide extra safety by verifying when a flame is present, verifying that the furnace is venting properly, and making sure the furnace is not too hot.

An oil system is a little different. Its components include:

Fuel Pump: The fuel pump pulls the oil from the tank into the burner motor.

Burner Motor: The burner motor spins to pull air and fuel into the combustion chamber.

Oil Nozzle: The oil nozzle vaporizes the oil as it is pushed through the nozzle with great force. The vaporized oil is mixed with air and a spark to create combustion.

Electrodes: The spark (mentioned above) comes from the electrodes and the ignition transformer.

Cad Cell: Cad Cells sense the presence of a flame.

Ignition Transformer: The ignition transformer sends high voltage through the electrodes, which produces a spark right at the oil nozzle.  The vaporized oil mixes with air and the spark produces a flame inside of the combustion chamber (heat exchanger).

Ventilation System

Finally, there is a ventilation system to exhaust the resulting gases out of your home. Low-efficiency systems typically use a chimney while high-efficiency systems use a motor to draw the exhaust out of the furnace through plastic (PVC) pipes.


Your furnace is designed with a variety of safety features to make it incredibly safe to operate, as long as your system receives proper maintenance from both you and B&L Ott. As furnaces become more efficient and more computerized, it becomes more important that they are not just cleaned, but thoroughly inspected.

When you schedule maintenance with B&L Ott,  will clean and inspect the entire heating system. We will check it’s capacity, efficiency, and safety.  Our technicians will look to improve your comfort, indoor air quality, efficiency and system reliability.  Your furnace keeps you warm from October to April – give your furnace the care it needs by calling B&L Ott today.