How Central Heating Works

The Basics

Central heating systems consist of five basic parts: air intake, a heater, ducts, vents and a thermostat.

Air Intake

Central heating works by bringing in air, warming it up and blowing the warm air out into your house. Your system will have one intake duct that pulls air in, usually through a vent near the ceiling.

Heater

The heater pumps cold air over a heating element. In electric heaters, this element is heated by running electrical current through it. In gas heaters, it's a gas-fed flame. Air comes in from the intake duct, flows over the element and then out through the ducts.

Ducts

Ducts are long, flexible tubes that carry the warmed air to the individual rooms in a house. Most of the time ducts are under the house.

Vents

Vents are small grates where the warm air is pumped into each room of the house. Because heat rises, they are generally located on the floor .

Thermostat

The thermostat has two jobs. It measures the temperature in the room and compares it to the desired temperature, then sends instructions to the heating system.