Furnace vs Boiler in St. Clair County, Illinois
When a furnace makes sense
If your house already has ductwork, a furnace is the straightforward choice. Most homes in this region were built with ducts already in place, and a furnace uses them to heat the whole house. It also handles central air conditioning through the same ducts, so one system covers both jobs.
When a boiler makes sense
If your home heats through radiators or in-floor pipes instead of ducts, a boiler is built for that and costs about 5% less to run here than a furnace. Winter nights average 26°F from December through February, and a boiler delivers steady, even heat through those months without needing ductwork added. It won't provide air conditioning, so you would need a separate way to cool the house in summer.
When a furnace makes sense
If your house already has ductwork, a furnace is the straightforward choice. Most homes in this region were built with ducts already in place, and a furnace uses them to heat the whole house. It also handles central air conditioning through the same ducts, so one system covers both jobs.
When a boiler makes sense
If your home heats through radiators or in-floor pipes instead of ducts, a boiler is built for that and costs about 5% less to run here than a furnace. Winter nights average 26°F from December through February, and a boiler delivers steady, even heat through those months without needing ductwork added. It won't provide air conditioning, so you would need a separate way to cool the house in summer.
Furnace
- Runs on
- Natural gas
- What it does
- Heats only
- Tax credit
- No federal tax credit since the end of 2025
Sources: U.S. Department of Energy · Internal Revenue Code
Boiler
- Runs on
- Natural gas
- What it does
- Heats only
- Tax credit
- No federal tax credit since the end of 2025
Sources: U.S. Department of Energy · Internal Revenue Code
Furnace wins in St. Clair County.
In the Great Lakes states, 78.8% of homes heat with a furnace, so most already have the ductwork it needs.
If your home already has radiators or in-floor pipes instead of ductwork, a boiler is still the better choice.
Find a contractor| Compared on | Furnace | Boiler |
|---|---|---|
| Cost to run here | Costs more to run | About 5% less to run |
| What it does | Heats only | Heats only |
| Homes in the Great Lakes states that heat with one | 78.8% | 7.7% |
| Handles a 26°F night | Yes | Yes |
Sources: U.S. Energy Information Administration, U.S. Department of Energy, NOAA
When a furnace makes sense
If your house already has ductwork, a furnace is the straightforward choice. Most homes in this region were built with ducts already in place, and a furnace uses them to heat the whole house. It also handles central air conditioning through the same ducts, so one system covers both jobs.
When a boiler makes sense
If your home heats through radiators or in-floor pipes instead of ducts, a boiler is built for that and costs about 5% less to run here than a furnace. Winter nights average 26°F from December through February, and a boiler delivers steady, even heat through those months without needing ductwork added. It won't provide air conditioning, so you would need a separate way to cool the house in summer.
A St. Clair County contractor will price both against your own house, your ductwork and your panel.
Tell us about the job
It takes about a minute.