Furnace Repair in Brooklyn
Gas furnace repair for brownstones, row houses, and two-families — no heat, won't start, short cycling, blower faults. Same-day when available.
Brooklyn Furnaces Fail in Predictable Ways
Most forced-air furnaces in Brooklyn live in a cellar or a tight utility closet, pull return air through ductwork that was added long after the house was built, and vent into a chimney that has seen a century of use. Dust and lint load the filter faster than the manual expects. Returns are undersized, so the furnace runs hot and trips its limit. A rooftop or yard condenser shares the same air handler, so a summer problem sometimes shows up as a winter one. We work on these systems every week in Park Slope, Bed-Stuy, Crown Heights, Bushwick, Bay Ridge, and across the borough.
This page is about forced-air gas furnaces. If your heat comes from radiators or baseboard on a hot-water system, that's a boiler — see boiler repair in Brooklyn. If your heat comes from a ductless head or a heat pump, see heat pump repair. Not sure what you have? Call and describe it — we'll tell you on the phone.
Before you call, our furnace not turning on guide explains what to notice about the startup sequence, and the Goodman and Coleman error-code guides decode the blinking light on the control board. Tell us what you saw — it shortens the diagnosis.
How We Diagnose a Furnace That Won't Heat
A gas furnace starts in a fixed order: the thermostat calls, the inducer motor starts and proves draft through the pressure switch, the ignitor heats or the spark fires, the gas valve opens, the burners light, the flame sensor proves the flame, and only then does the blower start. Where the sequence stops tells us where to look. A furnace that never starts the inducer is a control, power, or thermostat problem. One that lights and drops out three times before locking out is almost always the flame sensor or the gas supply. One that heats and then shuts down is an airflow or limit problem.
We read the stored fault codes off the control board first, then test the suspect component instead of replacing it on a hunch: ignitor resistance, flame-sensor current in microamps, pressure-switch operation against the actual draft, blower amp draw and capacitor value, static pressure across the filter and coil, temperature rise across the heat exchanger, and manifold gas pressure. On high-efficiency condensing furnaces we also check the condensate trap and drain, which block often in cellars. When a heat exchanger is suspect, we inspect it directly — a cracked exchanger is a safety issue and we will not run a furnace with one.
You get the repair scope and price in writing before work begins. Most single-component failures — ignitor, flame sensor, capacitor, pressure switch, thermostat wiring — are fixed on the first visit with parts from the truck.
What Furnace Repairs Cost in Brooklyn
Furnace repair cost depends on which component failed and how the furnace is installed. A flame sensor cleaning is a different job from a blower motor, and a blower motor is a different job from a control board on a two-stage furnace wedged into a 1920s cellar. Rather than publish a price menu that may not match your furnace, we diagnose first and give you a written repair price based on the actual failure.
Replacement is a separate conversation, and it's one we'll have honestly. A furnace under about 15 years with a single failed part is almost always worth repairing. A furnace past 20 years with a cracked heat exchanger, or one that has needed a repair every winter, usually isn't. When that's the case we say so and quote a replacement in writing — forced-air furnace installation is work we do ourselves. See furnace installation and replacement in Brooklyn for how we size, vent, and quote a new furnace, and what financing is available.
Common Furnace Problems We Fix
- No heat — thermostat calling, furnace never fires
- Furnace won't start at all (no power, tripped switch, failed control board)
- Ignition faults — hot-surface ignitor cracked, spark or pilot not lighting
- Flame lights then drops out (dirty or failed flame sensor)
- Short cycling — runs a few minutes, trips on the high limit, restarts
- Blower not running or running weak (capacitor, motor, ECM module)
- Intermittent heat — works some mornings, not others
- Pressure-switch, inducer motor, or venting faults on a locked-out furnace
- Thermostat or low-voltage wiring problems, especially after a thermostat swap
- Weak airflow from the registers — filter, blower, or duct restriction
- High-efficiency furnace tripping on a blocked condensate drain
- Gas valve or gas-pressure problems (tested, never guessed)
Furnace Systems We Service
- Standard 80% gas furnaces vented into a chimney or metal flue
- 90%+ high-efficiency condensing furnaces with PVC venting
- Single-stage, two-stage, and modulating furnaces
- Goodman, Coleman, Carrier, Bryant, Trane, Lennox, Rheem, Ruud, American Standard, York, and other makes
- Furnaces paired with a central AC coil and rooftop or yard condenser
- Note: forced-air furnaces only — for hot-water boilers see our boiler repair page
Why Brooklyn Calls Us for Furnace Work
- Brooklyn-based — cellar furnaces in brownstones and row houses are our daily work
- Real diagnostics: flame-sensor current, ignitor resistance, static pressure, temperature rise, gas pressure
- Common ignitors, flame sensors, capacitors, and pressure switches carried on the truck
- Written repair price before any work starts
- 30-day workmanship warranty on every repair
- EPA-certified and insured — COIs for co-op and condo buildings
What Brooklyn Says About Our Heating Work
4.8 stars from 79+ verified reviews
Furnace Repair Brooklyn — FAQs
Related Brooklyn Heating Pages
Furnace Not Turning On Guide
What to notice about the startup sequence before you call, and the safety limits.
View pageGoodman Furnace Error Codes
What each LED blink pattern means and which faults are urgent.
View pageColeman Furnace Error Codes
Flash-code guide for Coleman furnaces — safe resets and when to call.
View pageFurnace Installation & Replacement
When the furnace is past saving — sizing, venting, ductwork, and what the quote includes.
View pageBoiler Repair Brooklyn
Hot-water boiler repair for brownstones on hydronic heat.
View pageMaintenance Plans
Fall heating tune-up — catches ignitor and airflow problems before the first cold night.
View pageNo Heat? Call a Brooklyn Furnace Tech Now.
Same-day when available during the heating season. Day and evening emergency calls — hours vary.