Furnace Replacement in Dix Hills, NY

Three Dix Hills homes. Two in the attic and one in a closet. The December 2021 job replaced only the furnace, while the January 2022 and October 2026 jobs also replaced the cooling coil and outdoor condenser. Both 2021 and 2022 furnaces were 80% Rheem units rated 100,000 BTU.

• December 2021: the old attic furnace came out and an 80% Rheem rated 100,000 BTU went in, with the flue pipe modified and reconnected before start-up.
• January 2022: furnace, coil, condenser and thermostat replaced; the 100,000 BTU furnace went into a closet under a 4-ton coil, the existing line set was pressure-tested with nitrogen and reused, and an Aprilaire 8463 programmable thermostat went on the wall.
• October 2026: the second-floor furnace and coil in the attic were replaced with a new furnace and matched coil for a 4-ton system, plus a new condenser outside, a new gas line to the furnace and new flue pipe.

Many Dix Hills houses are large colonials and expanded ranches, and one furnace often heats a whole floor or more. Both of our earlier Dix Hills replacements used 100,000 BTU furnaces for that reason. Size still comes from a heat-loss calculation, not the old furnace's label, since insulation and windows change the load.

A furnace that is too big for its space heats in short bursts and leaves far rooms cool, while one that is too small runs nonstop on the coldest nights. In two-system homes, the upstairs furnace usually needs less capacity than the one serving the main floor, because heat rises and bedrooms are smaller. We size each unit for the rooms it serves.

Everything has to come out and go in through the attic access, and the furnace has to vent, drain and get combustion air up there. On attic replacements we disconnect the wiring, ducts, gas and flue, lower the old unit out, then set the new one and reconnect each connection.

In the October 2026 Dix Hills job, the primary and secondary drain lines and drain pan were reconnected under the new coil, the supply and return ducts were retrofitted to the new cabinet, and a new gas line and flue pipe were installed for the furnace. Attic furnaces also need a safe working platform and a light at the unit, which we check before quoting.

It depends on the cooling equipment's age and whether its coil fits the new furnace. In December 2021 we replaced only the Dix Hills attic furnace. In the January 2022 and October 2026 jobs, the coil and condenser went in with the furnace so the indoor and outdoor parts matched.

The coil sits on top of the furnace and the furnace blower moves the air for cooling, so the two are tied together. When the AC still has good years left, a furnace-only job keeps the cost down. When the AC is old or uses a phased-out refrigerant, doing both at once means one round of duct and wiring work instead of two. For whole-system projects in town, our Dix Hills heating installation page covers boiler and hydro-air jobs too.

Not always, but it is a good moment to check. The January 2022 Dix Hills job included a new Aprilaire 8463 programmable thermostat because the old one was being replaced with the rest of the system. In other homes the existing thermostat is reconnected and tested with the new furnace.

Two-stage furnaces and systems with separate upstairs and downstairs equipment need a thermostat that matches, and many smart thermostats need a common wire for power. We confirm each thermostat calls the right furnace before we leave. If you want to set it back at night, our post on turning the heat down at night explains how far.

The usual signs are age past about 15 years, repeat repairs, a damaged heat exchanger, rising gas use and rooms that never heat evenly. A single failed part, like the flame sensor we found on a January 2026 Dix Hills no-heat call, is normally a repair, not a reason to replace.

When a furnace reaches the point where repairs keep stacking up, we give you the repair price and the replacement price side by side so the choice is yours. Our Dix Hills furnace repair page covers common no-heat causes in the hamlet.

Dix Hills is unincorporated and part of the Town of Huntington, whose Department of Engineering Services handles building questions from its Main Street offices in Huntington. K2 does not file permits, so please check with that department before your replacement is scheduled.

New gas piping to an attic furnace, as in the October 2026 job, is worth mentioning when you call the town. We can share the furnace's model number and input rating once your quote is final.

Every Dix Hills furnace replacement is quoted in writing after a visit. Furnace size and efficiency, attic or closet access, venting, gas piping, duct retrofits and whether the coil and condenser are replaced together all change the figure. Our furnace and boiler replacement cost guide explains each one.

Financing is offered through Rheem KwikComfort, with credit provided by Synchrony Bank, subject to credit approval. We help register the new furnace with the manufacturer; see our warranty page. See finished work in the Dix Hills boiler, central air and ductwork replacement and the Dix Hills thermostat replacement. Read more on furnace replacement, furnace repair across Long Island and the Dix Hills HVAC hub.