How Does My Gas Furnace Work?

On a frosty winter’s day here in Texas, your gas furnace is hard at work, keeping your Marble Falls home warm and cozy. Feeling grateful? You’re not alone—it’s one of the most popular forms of heating, as American as apple pie.

In 1919, New Jersey inventor Alice H. Parker filed a patent for the first gas-fueled furnace. Years later, the basic technology is the same—only it burns less gas. In fact, modern furnaces burn at up to 97 percent efficiency, according to Consumer Reports. Keep this in mind if you’ve owned your heater for 10 years or longer.

Our team at All About Air could help you save big bucks on your monthly utility bill by performing a furnace replacement. And while we’re on the topic, we can help with your other HVAC needs: air conditioning, heat pumps, indoor air quality (IAQ), and more. All you need to do is call.

How a Gas Furnace Works

Furnaces that burn natural gas have four basic elements:

1. The Thermostat

Your thermostat is the eyes and ears of the operation. If it senses your home is below the target temperature, it sends signals to your furnace. Then, your furnace continues to cycle until your home is adequately warm. Finally, when it detects the desired temperature, the thermostat tells your furnace to stop running (until further notice).

2. The Ignitor

When your thermostat sends out a signal, the ignitor is the first to respond. Like the ignition starts your car—the ignitor starts your furnace.

If your heater is a decade old (or older), the ignitor might be a pilot light. The pilot stays lit 24/7, running on a small stream of natural gas. Newer furnaces have an electric ignitor, a considerably safer option. Electric ignitors are less risky because if your pilot goes out, you will quickly have a house full of gas fumes.

3. The Combustion Chamber

Next on the chain is the combustion chamber. This is where the ignitor lights the fuel. The natural gas becomes intertwined with oxygen supplied via a vent system or draft hood. The oxygen ensures that the fuel burns both cleanly and efficiently.

Besides taking in oxygen, the ventilation system pushes out exhaust through your flue. Economy flues are usually made out of galvanized steel. However, homeowners with polypropylene venting see long-term savings due to higher efficiency. The latter is also quite easy to install.

Whatever your flue is made out of—stay on top of maintenance. A clean flue ensures healthy air and prevents gas from getting squandered.

The Heat Exchanger

The combustion chamber emits heat, which gets collected by the heat exchanger. From there, the heat exchanger collects and distributes the treated air to your ductwork using burner-heated metal tubes.

When the tubes reach the right temperature, the furnace motor kicks on and begins blowing the air throughout your Marble Falls home with the help of fans.

High-efficiency furnaces have variable-speed blowers, which use less energy and allow tighter temperature control. These premium models may also have multiple heat exchangers, which helps your furnace use less fuel.

Remember to schedule seasonal maintenance—a cracked heat exchanger can lead to a dangerous carbon monoxide (CO) leak.

Need Service? We Have You Covered

All About Air is pleased to offer second-to-none heating and cooling services. Our certified HVAC specialists can perform repairs, maintenance, and installations. For prompt assistance, call our Marble Falls, TX, office at 830-308-5200 or request service online.