How Does A Furnace Work Exactly?

By Author: Carolyn Ethington
Total Articles: 49
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For most homeowners who have limited mechanical and technical knowledge, regular and dependable heat supplied from a furnace seems almost magical. Staying comfortable in the winter is something we all tend to take for granted: until the heater stops working! Its operation is really no mystery at all, of course: here are the basic ABCs of how a furnace works and why it's so important to keep yours in peak running order.

How It Works

The heat-producing component of a furnace is its burner. Most of today's gas units have one or two of these burners and their operation is regulated by a thermostat. When the temperature in your house dips below the level set on the thermostat, gas begins to flow into the unit and is then ignited electronically. After passing through a heat exchanger, the combusted gas exits the house through a vent.

Fresh air intake into the furnace is extremely important, because it is that air that is drawn into the unit through a duct system and heated in the hot chamber; for this reason, it is extremely important that the air intake vents in your home ...
... be kept free and clear of objects and dirt at all times. The heated air leaves the furnace and is re-circulated through your duct system, exiting into separate rooms through heat vents.

If you think about it, it's a pretty simple system: fresh air in, heated air out; fresh air in, heated air out. It is one continuous circle of air distribution. Your furnace filter captures a lot of the dust and other particulates that enter through the air intake vents and then tend to circulate continuously through the ducts: this is why, if you value healthy indoor air quality, that you need to change your filters at least every three months.

What You Can Do

A furnace requires regular maintenance, just like your car does. You wouldn't dream of running your car without oil or not checking the air pressure in your tires on a regular basis: your vehicle just wouldn't run properly. The same principle applies to your furnace: it need regular checkups from a heating professional along with periodic filter changes in order to function at peak efficiency and prevent breakdowns.


The spring and summer months are the perfect time to get your furnace tended to, since contractors are not slammed with requests for service like they are when it is cold out.

Now is the time to contact your Utah heating contractor or a contractor in the state where you live to make sure this essential appliance will be ready to go when you need it. It's not magic: it's just good common sense. Please visit our website to know more about our Utah heating contractor and air conditioning, electrical, plumbing and heating services.