“How do I know if I have a boiler or a furnace? What’s the difference?” 


While both furnaces and boilers heat your home, their heating methods differ. A furnace often called a “forced air” furnace, heats air and, using a blower motor, forces the air throughout the house with an air duct system. The majority of furnaces are powered by natural gas or electricity, though a few furnaces may use propane as fuel.

Boilers (hydronic systems) heat water and, with the use of a pump, send the hot water through pipes to metal baseboards, iron radiators, or radiant floor heating systems.  The heat from these fixtures then warms the air in each room of your home. A boiler may use steam, diverting it through pipes to individual radiators. Boilers may use gas, electricity, oil, or other fuels (example, wood pellets) to heat the water.

Pros and Cons

Experts measure a heater’s efficiency by the Annual Fuel Utilization Efficiency (AFUE) rate, indicated as a percentage. Higher AFUE indicates more efficient models. According to Home Advisor, AFUE ratings for various models of furnaces closely mimic those of high-efficiency water tanks and steam boilers. However, in forced air heating, sometimes as high as 35% AFUE is lost in air ducts. Boilers have no such loss of AFUE.

Are you considering installing a new heating system? Home Advisor found furnaces cost less on average than boilers with lower average installation fees. Once installed, boilers average less annual heating costs, evaluated for a northern climate, and run more efficiently. Adding the use of zone heating or an eco-friendly boiler, homeowners can further reduce their energy bills. 

Does your unit need repairs? Look to furnaces for lower repair costs. Both furnaces and boilers should undergo annual service tune-ups. In addition, homeowners should replace furnace filters at a minimum quarterly. Households in dusty areas or where indoor pets reside should change these filters monthly, adding to the cost of annual furnace maintenance. 

Is a member of your family sensitive to allergens? Furnaces use blowing air to heat or cool your home, sometimes creating a drafty environment.  Forced air can also distribute dust and allergens throughout your house and dry the environment in your home. Baseboards, iron radiators, or convection heat will keep the temperature consistent by offering steady heat.

Both furnace and boiler systems can effectively heat and cool your home. Contact an HVAC professional to determine which unit works best for you.