How a Gas Furnace Works

The Basics Behind How Your Furnace Works

You have your thermostat set to 22°C.  The thermostat will regulate the air temperature by engaging the furnace whenever the temperature drops below your specified amount.

When a modern furnace engages a few things happen:

1. First, the signal from the thermostat is received – Many programmable thermostats will make a “clicking” sound when the signal has been sent.

2. Fuel is then sent to the burners – At the heart of a gas furnace are burners, designed in such a way so as to maintain an even, controlled flame.

3. Once ignited, the furnaces internal sensors check to verify that all burners are lit – If a burner has not lit the entire mechanism will shut down and wait a predetermined period of time (varies based on each furnace) before attempting to reignite.

4. The burners heat a device called a heat exchanger – A heat exchanger more efficiently warms air (compared to the burners on their own).

5. A blower engages to circulate air through the heat exchanger – Once the heat exchanger has reached its operating temperature the blower motor is engaged, circulating air that has been sucked in through cold air returns.  This air is forced over/through the heat exchanger and then sent throughout the home.

6. A network of ducts directs the air throughout the house.

Modern furnaces are far more efficient at this process compared to older, antiquated furnaces.  They also utilize a series of fail safes and safety mechanisms designed to protect both your home and the furnace from failure. Learn more about your furnace from the experts at Action Furnace.

Note that the process for electric furnaces is nearly identical, though instead of burners an electric furnace uses resistance coils/tubing to create heat.

About Us

For 30 years we have been in the business of saving you money heating and cooling your home.

7650 County Road #2

Cobourg, Ontario 

K9A 4J7

Phone: (905) 372-0223

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