Furnace & Heating Repair
In a Chicago January, a furnace problem stops being a comfort issue fairly quickly. It becomes a pipes-freezing issue.
Most Chicago homes are heated by a forced-air gas furnace, and most no-heat calls come down to a handful of causes: a failed igniter, a dirty flame sensor, a pressure switch tripped by a blocked flue or condensate line, a control board fault, or a filter so clogged the furnace is overheating and shutting itself down on the limit switch.
That last one is worth knowing about, because it's free to check. A furnace that runs briefly then shuts off, over and over, is very often short cycling on a restricted filter. Before you call anyone — including us — look at the filter. If it's grey, replace it and see what happens.
There's a safety dimension here that we don't treat casually. A cracked heat exchanger or a blocked flue can put combustion products where they shouldn't be. If you have a carbon monoxide alarm sounding, that is not a service call — leave the building and call 911 or your gas utility from outside. We check flue integrity and combustion as part of diagnosis, and if we find something unsafe we'll red-tag it and tell you plainly, even when that's the answer nobody wants.
When this is likely your problem
What's included — and what isn't
Included in the quote
- Full diagnostic — ignition, flame sensor, pressure switch, limit, blower, and controls
- Repair or replacement of igniters, sensors, capacitors, motors, and control components
- Flame sensor cleaning and burner inspection
- Flue and combustion air check as part of diagnosis
- Filter and airflow assessment
- Verification the system completes full heating cycles before we leave
Quoted separately
- Furnace replacement and installation, quoted as its own project
- Chimney and flue liner repair or replacement
- Gas line modification and utility meter work
- Ductwork repair, sealing, and replacement
- Electrical work beyond the furnace's own components
- Carbon monoxide emergency response, which is 911 or the gas utility
What drives the price
We quote after diagnosis, not before. These are the factors that move the number most on this particular service:
- PARTAn igniter or flame sensor is a modest repair. A control board or blower motor is more.
- AGEParts availability on older units, and whether repair is proportionate to remaining life.
- SAFETYWhether diagnosis turns up a flue or heat exchanger issue that changes the scope entirely.
- ACCESSAttic, crawl space, or tight closet installations take longer to work on.
- TIMINGNo-heat calls during a cold snap may carry an after-hours premium, quoted first.
Chicago note
In a Chicago cold snap, a furnace failure becomes a frozen-pipe risk within hours, not days. If you lose heat in deep cold and can't get service immediately, keep cabinet doors under sinks on exterior walls open, let a trickle run from a far tap, and know where your main shutoff is. Those steps have saved plenty of people a much larger bill.
Related services
What the visit involves
Check the free things first
Filter, thermostat batteries, and the furnace switch. We'll tell you to do this on the phone.
Full diagnostic
Ignition sequence, sensors, switches, airflow, and combustion — not a parts-swapping guess.
Repair, or say it plainly
Most no-heat calls are a repair. Where a heat exchanger or flue issue changes that, you hear it straight.
Verify full cycles
We watch it complete several full heating cycles rather than leaving after one ignition.
Questions about furnace & heating repair
My furnace starts then shuts off after a minute. What is that?
That pattern is called short cycling, and the single most common cause is a clogged filter restricting airflow, which makes the furnace overheat and shut down on its limit switch. Check the filter first — it's free and it solves this more often than anything else. If the filter is clean, it's likely a flame sensor, pressure switch, or a flue restriction, all of which need diagnosis.
What do I do if my carbon monoxide alarm goes off?
Leave the building immediately, and call 911 or your gas utility's emergency number from outside. Don't go looking for the source, and don't wait for a service appointment. That's an emergency response, not a repair call. Once the situation is made safe, a heating contractor addresses the underlying fault.
Is it worth repairing an old furnace?
It depends on what failed and the unit's age. An igniter or flame sensor is a small repair worth doing on almost any furnace that's otherwise sound. A cracked heat exchanger is a replacement, not a repair, at any age. In between there's a judgement call about spending a meaningful fraction of replacement cost on an old unit, and we'll give you both numbers rather than deciding for you.
How often should I change the filter?
More often than most people do, and more often in winter when the system runs constantly. Check it monthly during heating season and replace it when it looks dirty rather than on a fixed schedule — homes with pets, renovations, or heavy use load filters far faster. It's the cheapest thing you can do for both efficiency and equipment life.
Do you handle boilers and radiators too?
Our heating work here is focused on forced-air furnaces, which is what most Chicago homes have. If you have a boiler and radiator system, call and describe it — we'll tell you honestly whether it's something we handle or point you to someone who specialises in hydronic systems.
Ready to get this looked at?
Call and describe what's happening. You'll get an honest read on urgency and cost before anyone comes out.