Furnace and Boiler Replacement Cost in NJ (2026): 80% vs 96%, Gas Boilers, Steam

What does a new furnace or boiler cost in NJ in 2026?

North Jersey — Bergen, Essex, Hudson and Passaic — runs roughly 15 to 20 percent above the state average on heating work. Labor costs more here and the houses are older and tighter to work in. Any quote built off a national average is going to move once somebody actually looks at your basement.

80% or 96% — which one is worth it?

AFUE is how much of the gas you buy turns into heat in your house. An 80 percent furnace sends a fifth of it up the chimney. A 96 percent furnace vents through PVC out the side wall and sends almost nothing up.

The high-efficiency unit costs $1,500 to $2,500 more installed and pays that back on a typical New Jersey gas bill over roughly eight to twelve years. Go 96 if you are staying long term and the basement has an easy path to a side wall. Go 80 if the budget is tight or the house goes on the market in a couple of years.

One catch nobody mentions. If your gas water heater shares the chimney with an 80 percent furnace and you switch to a 96, the water heater is left venting alone into an oversized flue. That orphaned heater needs a properly sized liner — $750 to $2,000. Any high-efficiency quote that ignores the water heater venting is incomplete.

Hot water or steam — what does a boiler cost?

New Jersey has three kinds of boiler houses: hot-water baseboard and radiators in postwar and newer homes, one-pipe or two-pipe steam in houses built from about 1900 through the 1940s across Bergen, Hudson and Essex, and oil, still common in older towns.

A standard cast-iron hot-water boiler runs $4,500 to $7,500 installed. A condensing modulating boiler — the wall-hung kind — is $7,500 to $12,000, and it only makes sense if the system can run at low water temperature. Put one on old cast-iron radiators running at 180 degrees and you own an expensive boiler that never condenses.

Steam is its own animal, and the boiler is not the expensive part. The near-boiler piping — header, risers, equalizer — has to be built exactly to the manufacturer's drawing or the system throws water into the mains and hammers all winter. That piping, a properly sized chimney liner, and hauling an 800-pound boiler out of a 1925 basement is why real steam replacements in North Jersey land at $8,000 to $16,000. The cheap quotes reuse the old piping.

Boiler repairs run $495 to $1,400 for the common items: a circulator pump, a zone valve, an expansion tank, a gas valve or a low-water cutoff.

Repair or replace? The rules we use

A decent gas furnace lasts 15 to 20 years in New Jersey. A cast-iron boiler goes 25 to 35. A steam boiler well maintained can go 30 or more. If yours is inside those numbers and the parts are still made, repair is usually the right call.

• Furnace under 12 years old and the repair is under about $800 — repair it
• Furnace 15 to 18 years old and the repair is over $1,500 — put the money toward a new one
• Any cracked heat exchanger, at any age — replace. That is a carbon monoxide risk and it is not repairable
• Boiler under 20 years old with a failed circulator, zone valve or expansion tank — repair, those are cheap parts on a long-lived machine

What about a heat pump instead?

Cold-climate heat pumps work in New Jersey now. They did not fifteen years ago. A single-zone ductless mini-split installed runs $3,000 to $5,000, a two to four zone system $5,000 to $14,000, and a ducted heat pump on existing ductwork sits in the $9,000 to $17,000 range as a full system.

They make the most sense in houses with no ducts — the capes and colonials on radiators or baseboard where adding ductwork costs more than the equipment. A mini-split gives those rooms air conditioning they have never had plus efficient heat down into the teens, with the boiler left in place for the deepest cold.

They make less sense with good ductwork, a working gas furnace and cheap natural gas. At current New Jersey rates a heat pump may not cost less to run, and we will tell you that instead of selling you the expensive answer.

Are there rebates for heating equipment in NJ?

Yes, and they change every year. New Jersey's Clean Energy Program has run rebates and low-interest financing for high-efficiency furnaces, boilers and heat pumps, and the utilities — PSE&G, New Jersey Natural Gas, Elizabethtown Gas, South Jersey Gas and JCP&L — have run their own on top. Heat pumps have carried the largest incentives in recent years.

We will not print a dollar figure, because funding runs out mid-year and the efficiency tiers get revised. Check the current terms before you sign, or ask us what homeowners are getting approved for right now. When you qualify we supply the paperwork the program needs.

Do I need a permit to replace a furnace or boiler in NJ?

Yes. Under the New Jersey Uniform Construction Code, replacing a furnace or boiler is a permit at your town's construction office — mechanical or plumbing subcode depending on the system, plus electrical if a circuit changes and fire subcode when the venting or chimney is altered. It gets inspected when the work is done.

We pull it, we meet the inspector, and it is in the price. An unpermitted heating install is a problem at closing and a problem with your insurer after a carbon monoxide incident or a fire. Ask any shop whether the permit is included and watch the answer.

Where these numbers come from

Furnace, boiler and mini-split ranges come from 2026 price pages published by New Jersey HVAC contractors in Union, Bergen, Hudson and Essex counties, national cost guides including HomeGuide, Fixr and Today's Homeowner, and our own 2026 quotes and installed jobs across North Jersey. Where the only published figure was national — steam boilers are the main one — we priced it for this market, where near-boiler piping and chimney liners push real jobs above the national band. Permit requirements follow the New Jersey Uniform Construction Code.

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