Central heating systems heat homes by using a primary heating appliance, usually either a boiler or furnace. In homes equipped with a boiler, heat is delivered to the rest of the home using hot water or steam transported through pipes to radiators. In homes equipped with a furnace, commonly known as a forced air furnace, the home is heated by warmed air that is circulated through air ducts throughout the home. Regardless of whether the heat source is a boiler or furnace, the central heating system is part of your home’s heating, ventilation, and air conditioning (HVAC) system.
In this article, we will focus on central heating systems that rely upon a forced air furnace. Read on to learn how central heating works.
How Furnaces Work
Furnaces generate heat by burning fuel — usually natural gas, propane, or oil. (Some forced air systems run on electricity.) As the fuel is combusted, the heat produced in the burner passes through a heat exchanger. Next, air from the home's ductwork is blown over the heat exchanger, warming the air. The furnace's blower then forces the heated air back into the supply ductwork, distributing it throughout the home.
Related: What Is the Difference Between a Furnace and a Boiler?
Central Heating Problems
Are you having forced air heating problems, or is your central heat not working? Central heating problems can be a major inconvenience. Once you understand the most common issues affecting central heating systems, you'll be able to troubleshoot them yourself and know what you can fix and what’s best left to the experts.
If your central heat is not working, it could be due to any number of factors.
Problem: Heater is blowing cold air
Check your thermostat and make sure it’s set to the correct temperature. Otherwise, the thermostat may be experiencing one of the following issues.
- Dirty air filter. Change your air filter, also known as a furnace filter, and see if that fixes the problem.
- Leaky ductwork. Check for leaks in the attic, and seal off any leaks and insulate your ducts accordingly.
- Pilot light issues. Make sure your furnace's pilot light is lit. If it won’t light, make sure gas is flowing to it. Check the gas valve and verify that it’s turned on. If your gas valve is on and your pilot light still won’t light, consult an HVAC repair professional.
- Lack of fuel. Check to make sure your furnace is getting the fuel it needs to run properly.
If none of these DIY fixes corrects the problem, contact an HVAC professional and have them examine your heating system more thoroughly.
