Furnace or Boiler?

People argue about whether furnaces or boilers are better. We think that both systems have their advantages, and we will never tell a client to replace one heating system for another, unless there are special circumstances.

The Important Differences Between Boilers and Furnaces

• Boilers have pipes. Furnaces have ducts.
• Boilers have radiators, convectors, or radiant pipes. Furnaces have registers and grills.
• Boilers have pumps instead of fans, with pump controls instead of fan controls.
• Boilers do not have air filters or electronic air cleaners.
• Boilers cannot have central air conditioning or humidification systems added.
• Boilers are connected to the house plumbing system (to provide water to the boiler system).
• There is a control to maintain the boiler water pressure at a desired level.
• There is often a device to keep the boiler water from getting back into our drinking water.
• Boilers have a safety device (pressure-relief valve) to prevent water pressure building up in the boiler system.
• Boilers have an expansion tank to allow the water to expand without creating high pressures when the water heats up.
• Some boilers have a safety device designed to turn the boiler off if the water level is too low.