Furnace Repairs on Long Island — 24/7

A furnace failure in the middle of a Long Island winter is more than an inconvenience. It is a safety concern. Pipes can freeze and burst within hours when indoor temperatures drop below 40 degrees. At Island Comfort HVAC, we treat every no-heat call as an emergency and prioritize getting your furnace running as quickly and safely as possible. Long Island heating outages — whether from a failed oil boiler or a dead gas furnace — can become dangerous fast in January and February when overnight lows regularly drop into the 20s. The distinction between an oil boiler vs gas furnace matters for diagnosis and parts availability: gas furnace failures most often involve ignitor, flame sensor, or inducer motor issues, while oil boiler problems typically center on burner assembly, oil pump, or aquastat failures. Our service territory covers both National Fuel Gas and LIPA/PSEG Long Island service areas across all of Nassau and Suffolk County.

Long Island's furnace landscape is distinct from most of the country. Natural gas is the dominant fuel after the wave of oil-to-gas conversions that swept through Nassau and Suffolk over the past two decades, but oil furnaces are still common in older homes in central Nassau and mid-Suffolk — homes built in the 1950s and 1960s before PSEG's gas distribution network expanded. The average furnace age across Long Island is 18 to 22 years, which means a significant portion of the installed base is approaching or past the point where repair costs compete with replacement costs. We give honest guidance on that decision every time.

We repair all types and brands of gas furnaces including Carrier, Lennox, Trane, Rheem, Goodman, Bryant, York, Amana, and Ruud. Our technicians carry the most common furnace repair parts on their trucks, including ignitors, flame sensors, inducer motors, gas valves, blower motors, and control boards. This allows us to complete the majority of repairs in a single visit.

Safety is our first priority on every furnace repair call. Before we start any diagnostic work, we check for carbon monoxide, inspect the heat exchanger for cracks, and verify the venting system is intact. A cracked heat exchanger can leak carbon monoxide into your home, which is colorless and odorless. We carry combustion analyzers on every truck and test exhaust gases as part of our standard diagnostic procedure.

Common furnace repairs we handle include ignitor replacement (the most frequent furnace failure), flame sensor cleaning and replacement, inducer motor replacement, blower motor repair, gas valve service, thermostat troubleshooting, control board replacement, and limit switch issues. Every repair comes with our 90-day parts and labor warranty.

Nassau and Suffolk County gas work must comply with the National Fuel Gas Code (NFPA 54) and local amendments. New furnace installs and certain gas line repairs require a permit from the applicable building department. We handle Town of Hempstead, Town of Oyster Bay, Town of Islip, and Town of Brookhaven permitting for any work that requires it. PSEG Long Island also offers rebates on certain qualifying heating equipment upgrades — we track current programs and handle the paperwork.

Oil-to-gas conversions remain one of the most common furnace-related projects on Long Island. Thousands of Nassau and Suffolk County homes still run oil furnaces installed in the 1960s and 1970s, particularly in central Nassau (Levittown, Wantagh, Hicksville) and mid-Suffolk (Centereach, Selden, Ronkonkoma). Converting to a high-efficiency natural gas furnace eliminates oil delivery costs, removes the buried or basement oil tank liability, and typically reduces annual heating costs by 25% to 40%. We handle the full scope of oil-to-gas conversion: furnace removal, new gas furnace installation, gas line connection, PVC venting, thermostat upgrade, and oil tank decommissioning coordination. The PSEG natural gas extension program may cover a portion of the gas line connection cost for homes not currently on the gas grid. Westbury is a particularly active oil-to-gas conversion market — National Fuel Gas lines reach every block and dozens of pre-1965 homes still run oil. See our dedicated <a href='/areas/nassau-county/westbury/' className='text-accent-500 hover:underline'>Westbury HVAC service page</a> for Westbury-specific furnace repair and replacement pricing.

For homeowners considering whether to repair or replace an aging furnace, we use a straightforward rule: if the repair cost exceeds 50% of the replacement cost and the furnace is over 15 years old, replacement almost always makes more sense financially. A new 96% AFUE condensing furnace will pay back the difference in gas savings within 4 to 6 years. We walk every customer through the math during the service call — no pressure, just the numbers.

Understanding furnace repair costs on Long Island helps you budget and avoid surprise bills. The table below shows the most common furnace repairs we perform across Nassau and Suffolk County, along with typical price ranges for 2026. These prices include parts and labor, and our diagnostic fee is waived when you proceed with the repair. Ignitor replacement: $150 to $250 — the single most common furnace failure; the silicon carbide or silicon nitride ignitor cracks after 5 to 8 years of thermal cycling. Flame sensor cleaning or replacement: $150 to $200 — a dirty flame sensor causes the furnace to light and then shut down within seconds. Inducer motor replacement: $350 to $600 — the draft inducer creates negative pressure in the heat exchanger to pull combustion gases through the flue; when it fails, the furnace will not start. Blower motor replacement: $400 to $700 — the blower pushes heated air through your ductwork; a failing motor produces weak airflow and may trip the high-limit safety switch. Control board replacement: $350 to $850 — the main circuit board manages ignition sequence, safety checks, and blower timing; failures often produce flashing error codes on the board LED. Gas valve replacement: $300 to $600 — the gas valve controls fuel flow to the burners; a faulty valve can cause no-heat or intermittent heating. Thermostat replacement or rewiring: $150 to $400 — wiring issues between the thermostat and furnace control board are common in Long Island homes where the original thermostat wire has degraded.

Long Island homeowners should also understand the seasonal patterns of furnace failures. The majority of furnace repair calls we receive happen during the first cold snap of the season — typically late November or early December. Furnaces that sat idle for 5 to 6 months develop issues that only manifest when the system fires for the first time under load. Flame sensors oxidize during the summer months. Inducer motors that barely functioned last March finally seize after months of inactivity. Blower capacitors weaken with age and fail when the motor tries to start at full speed after months off. This is why we recommend scheduling a fall furnace tune-up in October or early November — catching these issues before the first cold night means you never wake up to a 55-degree house.

For emergency furnace repair situations on Long Island — no heat when temperatures are below freezing — we prioritize same-evening dispatch. Our after-hours dispatch operates 365 days a year including holidays. The most dangerous period for furnace failures is January through early March, when overnight lows regularly drop into the teens across both Nassau and Suffolk County. At these temperatures, homes without heat risk frozen pipes within 6 to 12 hours, depending on insulation quality and wind exposure. If your furnace fails and temperatures are below freezing, set your faucets to a slow drip, open cabinet doors under sinks on exterior walls, and call us immediately. We will have a technician at your home as fast as possible.

We service furnaces in every Long Island town and hamlet, including high-volume service areas: Hempstead, Levittown, Hicksville, Massapequa, Farmingdale, Mineola, Westbury, Garden City, Syosset, Plainview (Nassau County) and Huntington, Babylon, Smithtown, Islip, Commack, Centereach, Patchogue, Bay Shore, Brentwood, and Deer Park (Suffolk County). Our Mineola headquarters provides rapid response to western Nassau, while our Suffolk-based service trucks cover Huntington east to Brookhaven. No matter where you are on Long Island, we can typically reach your home within 45 minutes during business hours.