Getting to Know the Components of Your Chicago Furnace

If you live in Chicago, you realize the value of a good furnace in the freezing winters.

But do you know how it works? Are you aware of the technology behind the furnace that produces heat and helps in maintaining the comfortable temperature in your living room?

In this article, we’ll aim to discuss the major components of your furnace and the individual functions of each component to help you better understand how your furnace works.

Heat Exchanger

After the combustion of gas in your furnace, the byproducts left are toxic fumes such as carbon monoxide, which absolutely should not be inhaled. A heat exchanger is a critical component in the furnace that separates these toxic gases before the air is circulated in the house. The heat exchanger consists of long, S-shaped tubes that vent out the toxic gases through the roof.

Blower Motor

The function of the blower motor is to force the heated air surrounding the tubes into the air ducts. This is a vital component that’s designed to serve its life for a number of years.

Gas Valve

Natural gas is supplied via pipes and is set at different pressures. At the entry into your home, the pressure is stepped down with the help of a gas valve. This corrected pressure (usually 3-5 inches of water column) is then carried to the furnace. The gas valve is also responsible for shutting the gas off when the safety switch fails.

Flue Pipe

The flue pipe assists the furnace to transport the toxic gases safely to the outside of the building.


The burner is the component of the furnace where the gas is ignited with a spark. It is the driving part of the furnace that enables the furnace to generate heat.

Pilot Light

In order to start a flame, gas furnaces must have a mechanism to ignite the gas. Previously, many furnaces used a pilot that burned continuously, lighting the gas when it comes on. Modern-day furnaces use a hot surface igniter (HSI) that glows red hot and ignites the gas.


This component of the furnace is placed next to the pilot light. Its primary function is to ensure that the pilot light is glowing. It acts as a sensor and will shut off the furnace if it cannot detect the pilot light.

Thermocouples tend to become dirty over time. If they become too dirty, they can lose their sensing abilities and this, in turn, will affect the overall performance of the furnace. Therefore, if not regularly cleaned, they will need to be replaced.

Flame Sensor

In most modern-day furnaces, thermocouples have been replaced by flame sensors. Flame sensors shut off the furnace if they cannot detect any heat. They also need to be kept clean for optimal performance.

Furnace Limit Switch

If a furnace becomes too hot, then the limit switch will turn off the gas for safety. For example, if the blower motor stops working and no air is circulated, the temperature inside the furnace will build up. In this situation, the limit switch will prevent the furnace from restarting until the problem is fixed.

Looking for an HVAC Maintenance Company in Chicago?

Do you need help with HVAC service and maintenance in Chicago? If so, Lakeview Heating and Cooling is the company to call.

We have a team of seasoned HVAC professionals who are well-versed in the repair and maintenance of all types of HVAC installation units, regardless of the make and type of unit.

Contact us today to schedule an appointment!