Furnace Repair on Long Island

Most furnace calls on Long Island come down to a short list of parts. The symptom usually points straight at the cause:

• The furnace tries to start but never lights. On gas furnaces this is usually a cracked or worn hot surface ignitor; on oil furnaces, a clogged nozzle, a fouled filter or electrodes that need setting.
• The burners light, then shut off within seconds. A dirty flame sensor is the classic cause, and it is one of the least expensive repairs there is. On oil furnaces the equivalent is a failing cad cell or primary control.
• A hum or rattle, then nothing. The draft inducer motor often seizes after a summer of sitting idle. Its bearings stick on the first cold start.
• A flashing code for the pressure switch. The switch, its hose, a blocked flue or a plugged condensate trap on a high-efficiency furnace can all cause it. We find the cause instead of just resetting it.
• Heat comes on, but the blower never runs (or runs weakly). Look at the blower motor, its capacitor and the control board relay.
• The furnace runs, then cycles off on high limit. Usually restricted airflow from a clogged filter, closed registers or undersized return ductwork.
• Soot, a smoky smell or a delayed "whoosh" on oil. This needs a combustion check, not a reset. Treat it as urgent.

A furnace repair visit follows the same order every time, so nothing gets guessed:

1. We ask what it is doing. When you call, tell us whether it tries to start, whether the blower runs and what the status light is flashing. That decides which parts go on the van.
2. Safety first. The technician checks for gas or flue gas leaks and confirms the venting is clear before running the furnace.
3. Diagnosis. They read the fault codes, test the ignitor, flame sensor, pressure switch, limit switches and motors with a meter, and watch a full start-up sequence.
4. A price before work. You get the cause, the repair, the price and whether it can wait, before anything is replaced.
5. Repair and test. After the repair we run the furnace through several cycles, check temperature rise and, on oil, take a combustion reading.

If the heat exchanger is cracked or the furnace cannot be made safe, we will tell you and shut it down rather than leave it running.

We quote each repair after diagnosis, so the price depends on what we find. The main factors are:

• The part. A flame sensor cleaning, an ignitor, an inducer motor and a control board are very different jobs.
• Fuel type. Oil burners need different parts and a combustion test that gas furnaces do not.
• Age and availability. Parts for older furnaces can take longer to source.
• Access. An attic or tight crawlspace furnace takes longer to work on than one in an open basement.
• Whether a second problem caused the first. A blocked flue that keeps tripping the pressure switch has to be fixed too, or the switch fails again.

Maintenance plan members get a repair discount and priority scheduling; see our maintenance plans.

Repair is usually right when the furnace is under about 15 years old, the heat exchanger is sound and the failed part is a wear item like an ignitor, sensor or motor. Replacement starts to make sense when:

• the heat exchanger is cracked, which cannot be safely repaired;
• the furnace is past 15 to 20 years and needed repairs in each of the last two seasons;
• parts are no longer available; or
• you are paying to heat a house that never feels warm, which often points to sizing or ductwork problems a new system can fix.

Our online Cost Estimator puts a gas furnace replacement at roughly $3,500 to $8,500 as a planning range; your actual quote depends on the house. For the replacement side, see furnace replacement and heating installation. If you are thinking about getting off oil entirely, read about oil-to-gas conversion. Financing is available through Rheem KwikComfort, with credit provided by Synchrony Bank, subject to credit approval. See financing for how it works.

Furnace repair in your town: see furnace repair across Long Island.

Replacing an old furnace? See furnace replacement.

Furnace blowing cold air right now? See what to check safely, or no heat at all.

Related services: boiler repair, 24/7 emergency heating and AC, furnace and boiler tune-ups, oil-to-gas conversion and water heater repair and replacement. Guides: furnace won't turn on? 7 things to check, why the heat smells like burning the first time and why a fall furnace tune-up pays off.