What's the Difference Between a Boiler and a Furnace?

January 12, 2020 By Excelsior Mechanical Blog

Boiler installation

Boilers and furnaces are different heating units, but most people don’t know what sets these two systems apart. Understanding each system can help to ensure your home is heated well, your HVAC system is as energy efficient as possible, and you’re making the wisest investment for your home. Discover the key qualities for each, as well as their pros and cons, to make an informed decision on a heating system.

Difference Between Furnaces and Boilers

The major difference between furnaces and boilers is how they work. Each heating system has distinctive properties and attributes which affect how they each distribute heat.
Furnaces are mechanical units that work by heating air, then using a blower to distribute that heated air throughout a duct system. They may encompass vents or registers in walls, ceilings or floors, which release warm air from the ducts into each room. These units can use natural gas, oil, or propane as a fuel source.

Boilers, on the other hand, use steam or hot water to heat a home. Steam boilers work by heating water until it turns into steam, which will then move through pipes until it’s released through radiators. These systems can use electricity, natural gas, wood, or oil for fuel. Hot water boilers work by heating water with a coil or moving hot water through radiant floor systems or baseboard radiators.
Although furnaces and boilers create and distribute heat differently, their energy efficiency is measured the same and dependent on the same factors. For example, an old furnace or boiler is much less energy efficient than a new one, and that efficiency may decrease as the unit ages.

Weighing the Pros and Cons of Furnaces and Boilers

As with any major home appliance, each heating system has its own set of advantages and disadvantages. For starters, some advantages furnaces have over boilers include:

  • Minimized leak risk, as furnaces typically only leak air
  • No risk of freezing or pipe bursts (heating pipes) during a prolonged power outage, since furnaces don’t use water to heat the home
  • Affordability in terms of purchase, installation, and maintenance
  • Quicker and simpler setup compared to boiler installation

Of course, there are also some advantages boilers have over furnaces. For instance, boilers offer:

  • Better indoor air quality (IAQ) because they don’t blow air, which can collect dust and allergens
  • Better energy efficiency and lower heating costs, as boilers use less fuel to heat a home
  • Less overall maintenance
  • Reduced noise compared to furnaces, which have blowers that often make noticeable sounds
  • More even, consistent heating

Furnaces and boilers are both worthy investments, but the one you choose may depend on your budget, heating needs, and home’s square footage. You should also take into consideration your preferences for comfort and maintenance when making this important decision. For more information on heating system installations, please contact us.