
Family-owned · 24/7 emergency
Heating & Air Conditioning Services in Naperville, IL
Your home is your fortress. We protect your comfort. Naperville splits across two counties, but it's one city: the same City of Naperville permit rules apply on both sides of town.
Family-owned
Built on trust. Not private equity.
Premium service
Quality workmanship you can rely on.
Honest pricing
Straightforward. No games.
Always on call
Emergency calls answered 24/7 — even Sundays.

Cooling
AC Repair, Installation & Maintenance in Naperville, IL
We service air conditioners, heat pumps, and ductless mini-splits throughout Plainfield, Naperville, and nearby suburbs. When your home stops cooling, we provide same-day diagnostics whenever availability allows.
AC Repair
$150–$600AC Installation & Replacement
$5,000–$10,000Ductless AC Installation & Mini-Splits
From $3,000/zoneAC Maintenance
$119

Heating
Furnace Repair, Replacement & Heating Maintenance in Naperville, IL
Our heating services cover furnaces, heat pumps, tune-ups, and the combustion safety checks that come with burning gas indoors. For no-heat emergencies, we answer the phone 24/7.
Furnace Repair
$150–$600Furnace Installation & Replacement
$5,000–$9,000Heat Pump Repair & Installation
$5,500–$10,000Heating Maintenance & Tune-Up
$119
Why local actually matters here
Local HVAC service for Naperville homes.
Naperville straddles the DuPage–Will county line — roughly the northern and western two-thirds of the city sit in DuPage County, the rest in Will. The county line doesn't change the permit, though: inside city limits the City of Naperville handles it on both sides (an unincorporated address with a Naperville mailing address goes through its county), and a like-for-like furnace or AC swap doesn't need one.
Naperville is Illinois' fourth-largest city, with around 150,000 residents — a bigger, denser market than the smaller suburbs we also serve. Same-day still means same-day here; a bigger city just means we schedule tighter, not slower.
Naperville's population boom really took off in the 1960s and never fully stopped, so the housing stock spans six decades in the same zip code — a split-level near the Historic District a few blocks from a new build in Ashwood Park or White Eagle, each with a completely different duct system. We don't assume a "typical Naperville house"; we run a Manual J on all of them.
What that actually means for your system
Common HVAC Problems We See in Naperville Homes
Naperville's housing stock spans six decades in the same zip code — a split-level near the Historic District a few blocks from a new build in Ashwood Park or White Eagle — so "what's normal for a Naperville house" isn't really one answer. The DuPage–Will county line runs through town too, but it doesn't change the job or the paperwork: inside city limits the City of Naperville handles permits on both sides. So we size and service the system to the actual house, whichever county it's in.
What we handle in Naperville
Everything FortHouse does, available to Naperville homeowners directly — not routed through a regional dispatcher two counties over.
AC repair & AC maintenance
Same-day AC repair when the air stops running cold, and AC maintenance dispatched to whichever side of the DuPage–Will county line the call is on — static pressure, refrigerant charge, amp draw, not just a filter swap.
Furnace repair & heating maintenance
Furnace repair and gas furnace repair with a combustion safety check on every visit, scheduled tight even across a city of roughly 150,000 — Illinois' fourth-largest.
HVAC installation & replacement
Full HVAC installation and replacement, Manual J–sized to the actual house — a split-level near the Historic District and a new build in Ashwood Park or White Eagle can need very different systems a few blocks apart.
Ductless mini-split installation
Ductless AC installation and mini-split installation for additions and converted spaces, a common need in Naperville's older, non-ducted homes closer to downtown.
Common questions
Naperville, IL — frequently asked.
What HVAC services does FortHouse offer in Naperville, IL?
AC repair, AC maintenance, furnace repair, heating installation, full HVAC replacement, and ductless mini-split installation — the same services listed on our services page, dispatched to whichever side of the county line you're on.
See all HVAC servicesDo you offer emergency HVAC repair in Naperville?
Yes — 24/7, including nights, weekends, and holidays. A furnace failure in January or an AC failure in a July heat wave doesn't wait for business hours.
Read more about our emergency HVAC serviceHow much does HVAC repair cost in Naperville, IL?
Most repairs run $150–$600 depending on the part and the failure. Every repair gets a written quote before we start work, based on an actual diagnostic, not a phone estimate.
See all HVAC servicesHow much does AC repair cost in Naperville, IL?
AC repair typically runs $150–$600, with the failed part driving the cost. Every repair gets a written quote before work starts, whether the call comes from the DuPage or Will County side of town.
AC repair in Naperville, ILHow much does furnace repair cost in Naperville, IL?
Furnace repair typically runs $150–$600, with the part driving the swing — an ignitor costs far less than an inducer motor. Every repair still gets a combustion safety check and a written quote before work starts.
Furnace repair in Naperville, ILDo you install new AC systems in Naperville?
Yes — a Manual J load calculation on every install, not a guess based on the old unit's tonnage. Naperville's housing spans six decades in the same zip code, so sizing math that works for a split-level near the Historic District rarely matches a new build in Ashwood Park or White Eagle.
AC installation in Naperville, ILDo you handle furnace installation in Naperville?
Yes — full furnace installation and replacement, sized to the actual house rather than whatever tonnage the old unit carried, with the venting, gas line, and combustion air done to code.
Furnace installation in Naperville, ILDo you offer furnace maintenance in Naperville?
Yes — a $119 fall tune-up covering the heat exchanger, burner, carbon monoxide, and safety controls, on older standard-efficiency furnaces and newer high-efficiency units alike. No permit needed on either side of the county line.
See furnace maintenance in NapervilleDo mini-splits need maintenance too?
Yes — the same annual service a central AC gets: coil cleaning, refrigerant charge check, and condensate drain clearing. A mini-split that's never been serviced loses capacity the same way a neglected central system does, and it's common in Naperville's older, non-ducted homes where a mini-split is the only cooling in that room.
See ductless mini-split installation detailsDoes it matter which county my Naperville house is in?
Not for HVAC work. Inside city limits, the City of Naperville handles permits on both sides of the DuPage–Will line (an unincorporated address with a Naperville mailing address goes through its county), and a like-for-like furnace or AC swap doesn't need one. The diagnostic, the pricing, and the crew are the same on either side of town.
See how HVAC replacement pricing and timeline workWhat areas near Naperville do you serve?
Plainfield, Yorkville, Bolingbrook, Oswego, Wheaton, Lisle, Minooka, Shorewood, and Aurora, alongside Naperville. If you're just outside that list, call anyway — we make exceptions for a reasonable drive.
See our full service areaHow we work
You call, we diagnose with real measurements, you get a flat written number before anything starts, then we fix it and put the post-repair readings on the invoice next to the originals. See the full four-step process.
Where we work
HVAC Service Areas Near Naperville, IL
We keep the radius tight on purpose. A tech who is twenty minutes away can actually get to you the same day, and already knows how the housing stock out here is built.
Not on the list? Call and ask — we make exceptions.
We service
Book a visit
(630) 318-6246