Choosing between a heat pump, central air and a furnace or boiler comes down to three things on Long Island: whether the house has ductwork, whether a gas main runs down the street, and what heats the house today. This guide compares the four systems we work on most, with planning prices from our cost guides and one of our own heat pump installs.
What is the difference between a heat pump, central AC and a furnace?
A central air conditioner only cools, moving heat from inside the house to the outdoor unit. A heat pump does the same in summer and runs in reverse in winter, pulling heat from outdoor air to warm the house. A furnace or boiler only heats, by burning gas or oil, so it pairs with separate cooling.
That is why the real comparison is usually a heat pump against a pair of systems: central air plus a gas furnace in a ducted house, or an oil or gas boiler plus window units or mini-splits in a house with baseboard or radiators.
How do the four systems compare for a Long Island home?
For running cost, a gas furnace is usually cheapest where a gas main reaches the house, and oil usually costs more. A heat pump typically costs less to run than oil, propane or electric baseboard and is close to gas in many homes. Only the heat pump and central AC cool the house.
| System | Running cost | Typical lifespan | Cooling | Long Island fit |
|---|---|---|---|---|
| Heat pump (ducted or ductless) | Usually below oil, propane and electric baseboard; close to gas in many homes | About 15 years; it runs all year | Yes | Homes leaving oil, homes without gas, additions and rooms the main system misses |
| Central air conditioner | Summer electricity only; heating is a separate bill | About 12 to 15 years | Yes | Ducted homes that already have a furnace |
| Gas furnace | Usually the lowest heating cost where gas is available | Up to about 20 years | No, pairs with central AC on the same ducts | Ducted homes on a gas main |
| Oil boiler | Follows oil prices, usually above gas | Cast iron boilers often 25 years or more | No, needs separate cooling | Older homes with baseboard or radiators and no gas service |
Running cost depends on your fuel and electric rates, the insulation and how the system is sized, so read the table as a direction rather than a bill. Lifespan depends on maintenance as much as on the equipment.
Can a heat pump heat a Long Island house in winter?
Yes, if it is a cold-climate model sized for the house. Cold-climate inverter heat pumps keep producing heat well below freezing, which covers a normal Long Island winter. Sizing matters more than with a furnace: a heat pump picked only for summer cooling can come up short on the coldest nights.
Many homes keep the existing boiler or furnace as backup and let the heat pump carry most of the season. That setup, often called dual fuel or hybrid heat, switches to the fossil-fuel system below a set outdoor temperature. Our dual-fuel heat pump page explains how the switchover works, and the oil to heat pump conversion page covers the options for oil-heated homes.
What do these systems cost to install on Long Island?
Our Cost Estimator puts a heat pump replacement at $6,000 to $15,000 and a new heat pump install at $12,500 to $20,000. A central AC replacement runs $5,800 to $13,500, a gas furnace replacement $3,500 to $8,500 and a gas boiler replacement $7,500 to $16,000. These are planning ranges, not quotes.
From our own billing, 8 ductless heat pump (mini-split) installs between January 2022 and October 2026 had a median of $8,291, with jobs from $2,950 to $26,077 depending mostly on the number of zones. The full breakdowns are in our heat pump cost guide, AC installation cost guide and furnace and boiler cost guide.
Rebates can lower a heat pump's price. They are claimed through a PSEG Long Island participating contractor or directly with PSEG Long Island; check psegliny.com for current terms.
What does a real heat pump replacement look like?
In May 2026 our crew replaced two old cooling systems in a Huntington home with one Daikin multi-zone heat pump. A ducted air handler in the attic serves the second floor and a ductless wall unit serves the living room, both on one 36,000 BTU outdoor unit. Because it is a heat pump, the new system heats as well as cools.
The homeowner first asked for an air conditioning quote. The house had two older indoor air handlers, each with its own outdoor unit. The crew removed all four pieces and installed 18,000 and 24,000 BTU indoor zones on the new outdoor unit, then wired a rooftop exhaust fan and repaired the sheetrock. The full write-up with photos is on the Huntington multi-zone project page.
Tip from Waseem Shahzad, Lead Technician: on that job Waseem replaced the condensate drain pump along with the equipment because he judged the old one unreliable. If your air handler sits in an attic and drains through a pump, have the pump checked whenever the system is replaced. A failed pump on a new system still means water in the ceiling.
Which system fits which kind of home?
A ducted house on a gas main usually does best with a gas furnace and central air, or a ducted heat pump if you want one system. Houses heated with oil or without gas service are where heat pumps make the most sense. Baseboard homes often add ductless heat pumps for cooling and shoulder-season heat.
- Ducted, gas available: furnace plus central AC, or a ducted heat pump with the furnace kept as backup.
- Ducted, oil or propane heat: a ducted heat pump, often with the old system kept for the coldest days.
- Baseboard or radiators, no ducts: keep the boiler for heat and add ductless heat pumps, or move most of the heating to a multi-zone system.
- Additions, finished basements, sunrooms: a single ductless heat pump zone, without extending the main system.
How should you decide?
Start with what heats the house now, whether there are ducts, and whether gas is on the street. Then compare installed prices against what you spend on fuel today. A load calculation on the house settles the sizing, and the sizing decides whether a heat pump can carry the winter alone or needs backup.
Our heat pump and central air installation pages explain how we size and quote each system. To have a technician look at your house, call (631) 414-7141.
Need a technician rather than a guide? See our heat pump service, or read about HVAC repair in Deer Park, NY. K2 answers 24/7 at (631) 414-7141.
