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

March 6, 2022 –

Boilers and furnaces: they both provide home heat, but they work in different ways.

Referring to your home heating system as a “furnace” has become the default, but if what you’re working with is actually a boiler, it’s important to know the difference between the two — as well as which you have.

Understanding the difference can save you money and simplify your home maintenance. Without knowing which system your home utilizes, there’s a risk of seeking assistance from the incorrect technician, leading to financial and time loss.

Here’s how to determine which your home is outfitted with:

The most straightforward clue is how air is circulated throughout your home.

Air vents

If you have air vents throughout your home, you have a furnace.

A furnace uses a heating unit to create warm air, which then circulates through the air ducts in your house until it reaches you through the vents. This is known as a forced-air system.

Radiators or baseboards

If your home has radiator heat or baseboard heaters to warm it, then you have a water boiler heat system.

This is also known as a hydronic system. The way a boiler operates is that water is heated in the boiler, then pumped to your hot water radiators/steam radiators and hydronic baseboard heaters. Eventually, that water returns to the boiler unit to begin the process again.

Now that you know what you have, learning to maintain the system is the next step. With regular care and maintenance, you can be sure that your system will continue running smoothly.

Furnace maintenance tips

For standard forced-air heating systems, make sure to replace your furnace filter about once monthly to ensure that your system is free of dust and other air impurities. Turn off your furnace before replacing the filter, and make sure to close the door or panel securely when you’re finished.

If you have a high-efficiency air filter, you can change the filter less often — just check occasionally and change as needed.

Boiler maintenance tips

When you have a boiler system, in order to feel heat from your baseboards, make sure that the damper is open and make sure there is nothing blocking the bottom of the unit.

It’s crucial to check the steam boilers’ water levels regularly — the leading cause of issues is low water levels. You’ll need to flush the boiler if you notice the water has taken on the orange color that suggests rust.

Ensure that the valve on your radiator is firmly in the on or off position. Hovering in between does nothing to control the heat output, but can cause strain to pipes and cause a loud banging sound.

When it comes to any heating system, it’s essential to keep the area around them clean and clutter-free. Doing so keeps the equipment clean and smooth-running prevents obstructions that could alter their output and makes maintenance visits stress-free.

We’re happy to help with your heating needs. Contact us at Paraco for easy, reliable home heat.


  1. Eileen Benson on December 9, 2019 at 3:23 pm

    Thanks for explaining that a boiler’s circulator is responsible for pumping the heat to the radiators. Ever since the weather started getting colder last month, I’ve noticed that my boiler hasn’t been able to heat the house to a comfortable level. I’m glad I read your article because now I feel a lot more prepared to talk with a boiler professional about the needed repairs!

  2. Zachary Tomlinson on March 3, 2020 at 1:28 am

    Thanks for helping me understand the difference between a boiler and a furnace. My mom told me to purchase a boiler for our house but I keep on confusing it between a furnace. What you said about how a furnace uses air to heat the home is news to me. I’ve always thought that they have been using the same technology.

  3. Bob on July 8, 2020 at 9:43 pm

    I didn’t know that boilers use a hydronic system to circulate water. My boiler has been broken for 3 months now and our house is freezing. I’ll have to consider getting a contractor to check to see if we need replacement parts for the rotator.

  4. Walter E. Bennett on February 18, 2022 at 11:38 am

    The furnace is the primary source of central heat, pumping hot air into every room and kicking the cold to the wayside. The boiler is supplying the hot water for morning wake-up showers and scrubbing pots clean. Boilers are typically more expensive than furnaces. KompareIt says boilers, which are more complex to install than furnaces, typically cost $2,500-$4,000 for a mid-range model, while high-efficiency boilers cost between $5,000-$10,000, including installation.

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