Furnace Installation in DeKalb, IL
A new furnace here will run from October through May every year. Tell us about the house, and a licensed contractor who covers DeKalb County will get in touch.
Tell us about the job
It takes about a minute.
DeKalb County asks a lot of a furnace
Winter nights here average 17°F, and homes need heat from October through May. That is eight months of the year your furnace has to run, not just a few cold weeks.
Most homes in DeKalb County heat with gas, and any new non-weatherized gas furnace built today has to reach at least 80 percent AFUE. That is the federal minimum, not a feature to shop for. The county has seen 17 winter storms and 105 damaging wind events over the past ten years, and across Illinois 16 percent of households lost power for 24 hours or more in 2024. A furnace installed here needs to get through a long season and start back up on its own once the power returns.
- 8 months
- October through May, your furnace is on duty
- 17°F
- the average winter night it heats against
- 72%
- of homes here heat with gas, so most furnaces here burn gas
- 80% AFUE
- the federal minimum any new unit must meet
NOAA nClimDiv, 1991–2020 normals
A high-efficiency gas furnace would save about $130 a year to run in DeKalb County compared with a gas furnace.
Estimates for a typical DeKalb County home, from EIA household energy data, Illinois fuel prices and NOAA climate normals. Your home will differ.
In Illinois, HVAC licensing for homes is left to the cities and towns.
DeKalb County does not run its own contractor licensing program, so whatever rule applies comes from the city or township where the house sits rather than from the county or the state. That means the requirement is not the same on every street. Some places require the installer to hold a local license, others just require the business to be registered, and some may have no rule at all. Nothing here is tested or recorded by the state of Illinois itself.
For a furnace installation, the protection that matters most is the permit. Most local building offices require one before a furnace is replaced, along with an inspection once the work is done, and that inspection is what checks the gas connection and venting, the part of this job that can hurt someone if it is done wrong. With 71.6% of DeKalb County homes heating with gas, that inspection is doing real work here, not just paperwork.
Source: Illinois General Assembly
- What size furnace does my house need?
- The right size depends on your home's square footage, how well it's insulated, your window count and type, and your local climate. A furnace that's too big will short cycle and wear out faster. One that's too small will run constantly and still leave rooms cold on the nights that drop to 17 degrees here. A contractor will run a load calculation on your actual house rather than go by square footage alone, since two homes the same size can need very different furnaces.
- How do I know it's time to replace my furnace?
- Age is the first sign, and if yours is old, parts get harder to find and failures more frequent. Watch for rooms that won't hold heat, a furnace that cycles on and off more than it used to, or a heating bill that's climbed without a reason. Homes here need heat from October through May, so a furnace that's struggling has 8 months a year to prove it. If yours is showing its age, a repair might get you through a season, but it's worth asking a contractor whether that money is better put toward a new unit.
- Is a high-efficiency furnace worth it?
- It depends on how long you plan to stay in the house and what furnace you have now. Furnaces made since November 2015 are required to hit at least 80 percent AFUE, so even a standard new furnace wastes less fuel than an older one might. A high-efficiency model uses less gas to produce the same heat, and with 71.6 percent of homes here heating with gas across 8 months of winter, that difference adds up. A contractor can walk you through the actual efficiency ratings and help you weigh the difference against your home's heating needs.