Furnaces vs. Boilers: Which Is Best for Your Home?

When it comes to heating your home and its hot water, you have a few options to consider. Many homes in the U.S. are heated by natural gas or electric furnaces, but some are heated by boilers — and some homes even have both. Furnace vs. boiler: which one is right for you? 

What’s a Furnace?

Furnaces use natural gas or electricity to heat air, which is then pushed throughout your home’s ducting system by a blower fan. Gas furnaces can burn natural gas or propane, while electric furnaces use heated coils to warm air — just like that hairdryer in your bathroom.

Furnaces are typically a home’s primarily central heat source. Hot water, meanwhile, is generated from a water heater that’s usually located in the garage of modern homes.

What’s a Boiler?

Boilers do exactly what their name implies — boil water to create steam. This heat source can be distributed throughout the home through radiant heat systems in the floor, or through baseboard radiators.

Boilers are usually powered by natural gas, propane, electricity, heating oil, or wood pellets.

Side-by-Side Comparisons: Furnaces vs. Boilers

In the section below, we’ve laid out some side-by-side comparisons to help you quickly identify the pros and cons of each type of heat system.

Cost

Installation costs are hard to figure exactly because no two jobs are alike, and appliance prices vary by efficiency and desired features.

• Furnace. Expect to spend between around $3,000 to $7,000 for a new furnace installation. The average cost is around $4,700.
• Boiler. A new boiler could set you back anywhere from $3,600 to $8,000, with an average cost of around $5,600.

Features

Furnaces and boilers are a bit like vehicles — the more you spend, the more features you get. Here are some important features to look for when researching new boilers and furnaces.

• Furnace. Variable speed blowers use less energy by adjusting air flow when you don’t need as much heat. Additional must-haves include EnergyStar certification for furnaces with an AFUE rating above 85%, an ignition system that doesn’t require a pilot light, and the ability to heat different zones in your home.
• Boiler. Top-of-the-line boilers have secondary heat exchangers, electronic ignition, and compact size to reduce incidental heat loss during cycling.

Ongoing maintenance

Both appliances require routine servicing, but furnaces have considerably more ongoing maintenance needs.

• Furnace. Routine furnace maintenance includes cleaning and oiling any moving parts, checking the thermostat and ignition system, removing any water in the drain trap, inspecting the blower, and replacing any parts as necessary. Annual service by a professional HVAC technician is highly recommended to extend the life of your appliance.
• Boiler. Boiler maintenance will likely significantly extend the life of your appliance. A technician will inspect the unit to ensure proper working order and that it’s venting properly if it’s an oil- or gas-powered appliance. The tech also can conduct a combustion test to ensure its operating at its highest efficiency. Condensing boilers will require servicing of the condensate disposal system as well. 

Energy efficiency

Appliance energy efficiency is denoted by its annual fuel utilization efficiency (AFUE) rating. AFUE is determined by taking the appliance’s heat output (measured in British Thermal Units [BTUs]) and comparing it to the amount of fuel it uses to produce that heat.

• Furnace. High-efficiency furnaces can have an AFUE of 90% or higher. Older, outdated furnaces may have an AFUE between 56 and 70%.
• Boiler. Look for a boiler with an AFUE of 90% or higher. Electric boilers operate between 95 and 100% AFUE since there’s no heat loss through a flue because the system doesn’t require venting. High-efficiency systems have sealed combustion chambers and employ secondary heat exchangers to recapture waste heat and boost efficiency.

Packaged systems: Furnace-Boiler combos

As the name suggests, combination furnace-boilers provide heat and hot water from a single appliance.

High-efficiency combi boilers provide heat through condensing technology — excess heat is recycled to preheat your home’s water. The boiler doesn’t have to work as hard to create hot water, and it’s recycling heat energy that is wasted in less-efficient units. Hot water is delivered instantly and on-demand from a tankless water heater.

These units can be a good fit for homes with limited space for large appliances like hot water storage tanks or attic furnaces, as well as for homeowners seeking ultra-efficient appliances.

Furnaces vs. Boilers — Making the Right Choice for Your Home

As we conclude our exploration of furnaces and boilers, it’s clear that both systems offer distinct advantages and suit different homeowner needs. Furnaces, with their extensive distribution networks and affordability, are ideal for homeowners seeking a straightforward and effective heating solution. Boilers, on the other hand, provide efficient, consistent heat and can double as hot water suppliers, making them a great choice for homes requiring a multifaceted heating approach.

Ultimately, your decision should be based on your home’s infrastructure, your personal comfort preferences, and energy efficiency requirements. Whichever system you choose, ensure it aligns with your long-term home heating needs, offering you comfort, efficiency, and reliability for years to come. Remember, consulting with a heating professional can provide valuable insights tailored to your specific situation, helping you make an informed decision between a furnace and a boiler.