When you think of a heating system, there is a good chance that you are only thinking of the main component; the furnace or boiler. While that is certainly true, there is a lot more to your heating system than you may realize. Each of the following components is necessary to your heating system. You should know what they are and why they are important.
Ducts, or ductwork, are all of the shafts that help channel hot air up into your home. These are connected to the top of the furnace. They spread out like a series of "arms" reaching toward several rooms on the first floor of the house, and then upward to reach rooms on the second story of the house. These ducts are only for forced air heating; boilers have their own "ducts" for heating that are very different from forced air heating ducts.
Vents are the openings into the rooms where the heat enters, and the cold exchange vents where colder air is returned to the furnace for heating. Since warm air rises and colder air drops to the floor, the cold air return/exchange events are necessary for keeping a constant flow of cold air to the furnace, and heated air to the hot air vents. It is one continuous circle, which is why you should never block a hot or cold air vent.
Your thermostat is key to controlling the temperature in your home, how much heat your furnace produces, and how often the furnace kicks on to keep your home a constant temperature at specific times. Things have become so sophisticated with thermostats that you can now program them for all times of day and/or night, and in some cases, even program them remotely from your smartphone or tablet. Without the thermostat, there is no way to turn on the heat and signal the furnace to work.
The Fuel or Power
Heating systems all have one thing in common. They need something to power them and/or something to fuel them. That fuel/power can be electricity, oil, natural gas, propane, etc. Without the fuel or the power, your furnace will not run. It cannot produce hot air, and it will not send that hot air upward through the ducts into your home. For those who heat their home with gas or oil fuels, that means you also have to have holding tanks for the fuel