Furnace repair in Chicago's western suburbs
The short answer
Most furnace repairs in Chicago's western suburbs run $150–$600, after a $119 diagnostic during regular hours; after-hours emergency calls carry additional fees. Four parts cause most no-heat calls: the ignitor, flame sensor, pressure switch, and inducer motor. All four ride on every truck, so most repairs finish the same visit. Replace instead when a repair costs more than half of a new furnace.
Written by Jenna Fortman, Owner of FortHouse Heating & Cooling. Installed by EPA 608 and NATE-certified technicians.
How much does furnace repair cost?
| Failed part | What you notice | Price | What the repair involves |
|---|---|---|---|
| Ignitor | Burner won't light | Low end of $150–$600 | Replacing a cracked or weak ignitor, the single most common cause of a furnace that won't start at all. |
| Flame sensor | Lights, then locks out | Within $150–$600 | Cleaning or replacing a sensor fouled by carbon, which the control board reads as a failed ignition. |
| Pressure switch | Won't start | Within $150–$600 | Testing the switch and the venting it's checking. A stuck switch is a safety feature doing its job. |
| Inducer motor | Never tries to light | Upper end of $150–$600 | Replacing the motor that pulls combustion air through before ignition. |
The range comes down to which part failed and how accessible it is. Every repair gets a written quote naming the specific part before any work starts, and after-hours emergency calls carry additional fees.
Should you repair or replace your furnace?
Run the 50% rule: if a repair costs more than half of what a new furnace would, or the furnace's age times the repair cost tops $5,000, replacement wins on value.
Repair is likely right when
- Repair estimate is under $600 and the furnace is younger than 15 years.
- This is the first repair this heating season.
- AFUE is 80% or higher and the gas bill hasn't climbed.
Replacement usually wins when
- A cracked heat exchanger — replaced, not repaired, full stop.
- This is a second repair in one heating season.
- The furnace is past 15 years old and AFUE is under 80%.
What happens on a furnace repair visit?
Before the visit
You call, we listen
Describe the symptom. We'll tell you on the phone whether it sounds like a worn part or a conversation about replacement. Same-day appointments when availability allows, 24/7 for no-heat emergencies.
The visit
Diagnosis with real readings
Ignition and flame-sensor diagnosis, a heat exchanger inspection, a carbon monoxide safety test, and gas pressure verification, on every visit, not as an upsell.
A written quote naming the part
Flat-rate pricing on paper before any work starts. No work begins without your signature.
The repair, usually same visit
The four parts behind most no-heat calls are stocked on every truck, which is the difference between a same-visit repair and a second appointment.
After
Proof it's fixed
Post-repair readings go on the invoice next to the originals, so you can see the problem closed, not just take our word for it.
Why does a local furnace repair crew matter in the western suburbs?
Based in Plainfield
FortHouse runs furnace repair calls across the western suburbs every day, not occasionally. The crew that answers the phone is the crew that shows up, not a dispatcher routing you to whoever's free two counties over.
Real emergencies
No heat with dangerously cold weather outside, especially with anyone vulnerable to cold in the house, is a real emergency, and we answer 24/7. A furnace that's still heating, just less well, can usually wait for a regular appointment and skip the after-hours fees.
What are the signs your furnace needs repair?
A few of these point straight at a specific failed part; check the filter first regardless, since it's the cheapest possible cause and rules itself out in under a minute. The fuller version of this list, covering both furnace and AC symptoms together, is here if you're not sure yet which system is actually the problem:
- [No heat at all](/blog/furnace-wont-turn-on), especially if the blower runs but no warm air follows — usually an ignition failure, not a total system death.
- Blowing cold or lukewarm air instead of shutting off cleanly between cycles.
- [Short cycling](/blog/furnace-short-cycling) — firing for a few minutes, shutting off, repeating — one of four specific, diagnosable causes, not random wear.
- Banging, screeching, or a repeated clicking that doesn't resolve on its own — usually an ignition or blower problem that won't fix itself.
- A yellow or flickering flame instead of steady blue — a combustion issue, and worth knowing the carbon monoxide signs that can come with it.
- A gas bill that's climbed with no change in weather or thermostat schedule — a furnace losing efficiency as a part starts to fail.
What should a furnace repair visit check?
Four things, every visit, not as an upsell: ignition and flame-sensor diagnosis (the two most common no-heat causes), a heat exchanger inspection (the one failure that can put combustion gases into the air), a carbon monoxide safety test, and gas pressure verification. A visit that skips straight to "it needs a part" without checking these isn't a shorter version of the same service — it's a different, less thorough one wearing the same name.
Which parts cause most no-heat calls?
Worth knowing what's actually failing, not just that something is:
- Ignitors — the component that lights the burner. A cracked or weakened ignitor is the single most common cause of a furnace that won't start at all.
- Flame sensors — confirm the burner actually lit. Carbon buildup over a season makes them unreliable, which the control board reads as an ignition failure and responds to with a safety lockout, not a fire.
- Pressure switches — verify the venting is actually pulling exhaust before the gas valve opens. A stuck or miswired switch is a safety feature doing its job, even though it presents as "the furnace won't turn on."
- Inducer motors — pull combustion air through the system before ignition. When one fails, the furnace often won't attempt to light at all, since the pressure switch never confirms proper draft.
When is furnace repair an emergency?
No heat with dangerously cold weather outside, especially with anyone vulnerable to cold in the house, is a real emergency — see the full breakdown of what qualifies and what can wait. A furnace that's still running, just less effectively, almost always can wait for a normal appointment instead of an after-hours one.
We answer the phone 24/7. The diagnostic is $119 during regular hours, and after-hours emergency calls carry additional fees, which is the practical reason to book a furnace that's still heating for the next regular appointment.
When is replacement the better call?
Not every furnace problem is worth fixing indefinitely — see the repair-or-replace breakdown above for the specific signals, and real replacement pricing and what installation day covers for the other side of that math once it points that way.
What should you check before booking a furnace repair company?
A few real questions separate a company solving your problem from one selling you a furnace:
- Will they name the specific failed part before quoting a price? A company that skips straight to a number without diagnosing anything is guessing, not repairing.
- Is the diagnostic visit itself real, or a loss leader? A price far under the cost of an honest visit isn't a discount — it's a sales call with a wrench in hand, and the upsell is the actual product.
- Are they licensed to pull permits in your specific town? Furnace work involving gas line or venting changes often requires one from city or village hall, and a company that doesn't know your town's rules is a company still learning them on your job.
- Who actually owns the company? We're family-owned, not backed by private equity — a distinction that shows up in whether the incentive is to fix your furnace or hit a sales quota.
Where does FortHouse repair furnaces?
Every city in our service area has its own furnace repair page covering local housing stock and response times.
- Furnace repair in Plainfield, IL
- Furnace repair in Naperville, IL
- Furnace repair in Yorkville, IL
- Furnace repair in Bolingbrook, IL
- Heating repair in Oswego, IL
- Furnace repair in Wheaton, IL
- Furnace repair in Lisle, IL
- Furnace repair in Minooka, IL
- Furnace repair in Shorewood, IL
- Furnace repair in Aurora, IL
Furnace repair questions
How much does furnace repair cost?
Most repairs run $150–$600 depending on the part and how accessible it is. Every visit gets a written quote naming the specific failed part before work starts, not a phone estimate.
How do I know if my furnace needs repair or replacement?
Run the 50% rule: if a single repair costs more than half of a new furnace, or the furnace's age times the repair cost tops $5,000, replacement wins on value. A cracked heat exchanger or a second repair in one season pushes the decision toward replacement even when the math is close.
What are the most common furnace problems?
A failed ignitor, a dirty flame sensor, a stuck pressure switch, or a failed inducer motor account for most no-heat calls. All four are diagnosable and usually fixable in a single visit.
Is no heat always an emergency?
It's a real emergency when it's dangerously cold outside, especially with anyone vulnerable to cold in the house. A furnace that's still heating, just less effectively, can typically wait for a scheduled appointment instead of an after-hours call.
How much does emergency furnace repair cost?
The repair itself falls in the same range, with most repairs at $150–$600. The diagnostic is $119 during regular hours, and after-hours emergency calls carry additional fees. If the furnace is still heating, booking the next regular appointment avoids those fees.
Why is my furnace blowing cold air?
Most often the blower is running but the burner isn't lighting or staying lit: a cracked or weak ignitor, or a dirty flame sensor that makes the control board shut the burner down as a safety lockout. Check the filter first, since it's the cheapest cause to rule out. If the air still runs cold, a diagnostic names the failed part before anything gets replaced.
How much does it cost to replace a furnace ignitor?
An ignitor sits at the low end of the $150–$600 range most furnace repairs fall in. It's one of the four parts we stock on every truck, so it's usually replaced on the same visit, with a written quote naming the price before any work starts.
Do you offer same-day furnace repair?
Yes, in most cases, plus 24/7 emergency service for genuine no-heat situations. We stock the parts behind most common failures — ignitors, flame sensors, pressure switches, inducer motors — on every truck.
What areas do you cover for furnace repair?
Plainfield, Naperville, Oswego, Yorkville, Bolingbrook, Wheaton, Lisle, Minooka, Shorewood, and Aurora, plus the rest of Chicago's western suburbs. If you're just outside that list, call anyway — we make exceptions for a reasonable drive.
Is there furnace repair near me that comes same-day?
Yes — we run furnace repair calls across the whole western suburbs service area every day, not occasionally, with same-day availability in most cases and 24/7 emergency service for genuine no-heat situations. The crew that answers the phone is the crew that shows up, not a dispatcher routing you to whoever's free two counties over.
Sources
Prices are FortHouse's own published installed ranges, last updated September 25, 2026. Your written quote follows a home visit, not a phone call.