What’s the Difference between a Boiler and a Furnace?
Posted: December 21, 2015

Posted: December 21, 2015
Posted by: Gerald Kuller, Home Comfort Manager
Most people refer to their heating system as a furnace, but that’s a totally different system from a boiler. They both keep you warm, but there are some tips you should know for each. So, do you have a boiler or a furnace?
Do you have a furnace?
A furnace refers to the heating unit in a warm air, or forced air, system. After air is heated in the furnace, a blower forces it through ducts. The warm air is then released through vents or registers in your home.
Do you have a boiler?
If you have a hot water (hydronic) system, water circulates around your boiler’s combustion chamber. A circulator pumps the hot water through pipes to heat baseboards or radiators. Eventually, the water returns to the unit to begin the cycle again. If you have a steam system, the boiler turns the water into steam, which then rises through pipes to radiators.
Hot tips for furnaces
- All warm air systems have filters to screen out dust and other impurities. If you have a standard throwaway filter, replace it about once month throughout the year. Make sure the furnace is off before changing the filter. After you’ve changed the filter, make sure the furnace door/panel is properly closed. Higher efficiency air filters require less maintenance and can be taken out and cleaned as needed.
- If you have a whole house air cleaner connected to your furnace, get the most out of it by keeping the thermostat setting to “on” instead of auto. This provides continuous circulation and filtration of indoor air and helps maintain a balanced temperature throughout your home.
Hot tips for boilers
- If you’re not getting heat from a baseboard, check to see if the damper is open. Make sure the bottom of the unit isn’t blocked by heavy carpeting.
- For steam systems, check the boiler’s water gauge periodically. Low water levels are a leading cause for shutdowns. Steam boilers should also be “flushed” when the water in the gauge looks rusty. Contact us if you’re not familiar with this procedure.
- A radiator valve has only two positions, on and off. Keeping the valve’s handle in between does not regulate the temperature but can strain the pipes and produce a hammering sound.
Important tips for all heating systems
- Keep the area around your system as clean and clutter-free as possible. Never store anything flammable near your system.
- Keep registers, baseboards or radiators clean and unobstructed to ensure maximum air flow.
If you think it’s time to replace your old furnace or boiler, please contact us today for a free estimate. You can read more about your options in new heating equipment here.