How Much Does Furnace Replacement Cost?

A new gas furnace for an average-sized home runs $3,800 to $10,000 installed, in line with national contractor survey data (Angi, 2026). Electric furnaces run lower, $1,700 to $7,100, and boiler replacement sits at $3,700 to $8,300, rising toward $12,000 for high-efficiency models.

What moves your quote inside that range: the fuel, the efficiency rating, whether the venting has to change, the state of the ductwork, and how much of the job is gas and electrical work rather than the furnace itself. In Philadelphia there is also a rebate worth knowing about before you choose the efficiency tier.

Furnace Replacement: What It Costs

What you are replacing	Typical installed cost	Source
Gas furnace, average-sized home	$3,800 to $10,000	Angi, 2026
Electric furnace	$1,700 to $7,100	Angi, 2026
Oil furnace	$3,800 to $10,000	Angi, 2026
Boiler replacement	$3,700 to $8,300, up to $12,000 high-efficiency	Angi, 2026
Furnace and air conditioner together (full HVAC)	$5,000 to $22,000, average $7,500	Angi, 2026
New or replacement ductwork, if required	$2,000 to $7,500	Angi, 2026
Labor for HVAC installation	around $1,500 on average	Angi, 2026

None of those are our prices. We do not publish a furnace price list, because the honest answer before a site visit is a range from someone else's survey data, which is exactly what the table above is.

What Drives the Price

The furnace itself

Fuel type

This is the first breakdown in any quote, and it typically decides more of the price than the brand does. Gas is the default across most of Philadelphia and much of New Jersey, and it sets the mainstream range. Electric furnaces cost less to install and more to run in this climate. Oil furnaces cost about what gas ones do to install, but add a tank, deliveries and annual combustion service.

Efficiency rating (AFUE)

This is where the pricing of the different types separates. AFUE is the share of the fuel's energy that ends up as heat in the house. A condensing furnace at 95 to 98 percent AFUE costs more than an 80 percent unit and returns it monthly. ENERGY STAR notes that a qualified furnace is about 15 percent more efficient than a conventional one. In Philadelphia this choice also affects your rebate, which is covered below.

Venting changes

This is the cost most homeowners do not see coming. Moving from an 80 percent furnace to a 95 percent condensing model changes how the appliance vents: instead of a masonry chimney it needs PVC intake and exhaust pipes run to an outside wall. In a rowhome or a finished basement, that routing can be the difference between an easy job and a complicated one. If the chimney also serves the water heater, that appliance's venting has to be reassessed too.

Sizing and the load calculation

Older furnaces were sized by rules of thumb; modern practice is different. Capacity comes from an ACCA Manual J load calculation, not from matching the BTU rating of the old furnace. Old furnaces were routinely oversized, and copying that number forward buys you short cycling, uneven temperatures and a shorter equipment life.

Ductwork condition

Ducts that leak or are undersized cap what any furnace can deliver. Replacement or major sealing work runs $2,000 to $7,500 on its own, and this is the single most common reason two quotes differ by thousands.

Gas line and electrical work

A larger or relocated furnace may need a resized gas line, and new equipment needs a properly sized circuit. Both are licensed trades and both belong as separate line items.

Permits and removal

Philadelphia requires a mechanical permit from L&I for equipment replacement beyond like-for-like parameters, and New Jersey requirements vary by township. Removal and disposal of the old unit is a real cost that some quotes hide and others itemize.

Signs You Are Paying for the Wrong Thing

• Sizing by square footage or by the old unit. Ask for the Manual J result. An oversized furnace heats in bursts, leaves cold rooms, and cycles itself to an early death.
• A high-efficiency quote with no venting plan. If nobody has explained where the PVC vent will run, that scope has not been priced.
• Ductwork problems noted verbally but absent from the quote. The cost has not disappeared; it has been deferred to you.
• An efficiency upsell with no payback argument. Ask what the annual saving is on your gas usage at your AFUE step. If the contractor cannot estimate it, the upsell is not grounded in anything.
• No mention of the chimney. If the old furnace shared a flue with the water heater and the new one vents in PVC, that flue is now oversized for a single appliance and needs addressing.

Planning the Replacement, Not Just the Purchase

Several factors determine where in the range your project lands, and most of them can be established before anyone quotes. The size of the house and its heat loss determine the output required. Efficiency level and product line decide the cost of the unit itself. The condition of existing ductwork, the venting route, whether the electrical service needs additional work and how accessible the equipment is all impact labor. Installing in an unfinished basement is a different job from installing in a crawl space or a closet.

It also helps to think in terms of overall cost rather than the upfront figure alone. A higher-efficiency unit costs more to install and less to run, and utility rebates can close part of that gap depending on the model and the program in force. Ask each contractor to provide a complete written proposal - equipment, labor, permit, thermostat, disposal of the old unit and any additional services - so you can compare like with like, and ask what would change the price once the old furnace is out. A professional who explains that clearly before the work saves you the surprise afterwards.

How to Compare Quotes

Before you hire anyone, make sure the written estimate contains the information below. A quote without it cannot be compared to anything.

• The load calculation result and the resulting BTU output
• Make, model, brand and AFUE rating of the proposed furnace
• Venting plan, including any change from chimney to PVC and its routing
• What happens to the water heater's venting if it shared the flue
• Ductwork inspection findings, with any work priced separately
• Gas line and electrical scope
• Permits, inspection, old-unit removal and disposal
• Thermostat, and whether a new one is included
• Labor warranty length, manufacturer warranty registration, and whether the company carries liability insurance for the work

Good, better and best should differ by equipment, not by quietly dropping the permit, the duct sealing or the venting. The question that exposes a thin bid quickest: what did the load calculation come out at, and what changes about the venting with this model?

Ways to Bring the Cost Down

Take the Philadelphia gas rebate seriously. PGW EnergySense pays $400 for a furnace at 95% AFUE or better, $1,000 for a 94% boiler and $1,400 for a combi boiler, with higher amounts of $800, $1,400 and $2,000 for income-qualified customers under its Affordable EnergySense tier. The program period runs from 1 September 2024 through 31 August 2027, and rebates are awarded first come, first served subject to available funds. That rebate is a direct argument for choosing the condensing furnace over the 80 percent model.

Know what is gone. The federal 25C Energy Efficient Home Improvement Credit ended for equipment placed in service after December 31, 2025. It is not available on a 2026 furnace. Pennsylvania's state-run Home Energy Rebates have also not launched: as of May 2026 the Department of Environmental Protection was still awaiting federal approval.

In New Jersey, check the state program. New Jersey's Clean Energy Program runs whole-home incentives tied to a home energy assessment, along with 0% financing. Confirm current terms directly, as they are revised periodically.

Plan the purchase, and budget for it. Late spring and summer are when furnaces are cheapest and installers have time. A furnace bought during the first hard freeze is bought from whatever is on the truck.

Replace heating and cooling together if both are near the end. One mobilization and one permit process, and the indoor coil ends up matched to the new equipment.

Spread the payment. Synergy3 Home Solutions offers financing with approved credit, including 0% options, and runs periodic promotions on qualifying system replacements; see our current offers.

Furnace Costs in Philadelphia and New Jersey

Venting is the local variable that surprises people most. Philadelphia rowhomes were built around masonry chimneys, and a great many still have an 80 percent furnace venting into one. Going condensing means finding a path for two PVC pipes to an exterior wall, through a finished basement in a house with party walls on both sides. It is entirely doable, and it is real labor that belongs in the quote.

The second local variable is what else is on that chimney. When the furnace stops using the flue, a gas water heater left on it alone can vent poorly. A competent contractor raises this before installation day rather than after.

In South and Central New Jersey the housing stock is different but the theme is the same: Cape Cods and split-levels usually have ducts, often running through unconditioned attics, and a new furnace will not fix heat lost up there. Duct sealing frequently does more for the upstairs bedrooms than the equipment upgrade does.

Synergy3 Home Solutions has been replacing heating systems across this region since 2006, with NATE-certified technicians and a load calculation on every job. See Furnace Replacement for what our process covers.

Get a Written Price for Your House

Published ranges tell you whether a quote is sane. A site visit tells you what your house needs and what the venting will actually involve. Get in touch with Synergy3 Home Solutions for a free replacement estimate. Family-run out of Philadelphia, 20 years in the trade, a 4.9-star rating, and 500+ Google reviews. Hours are Monday to Friday 7:00 am to 7:00 pm and Saturday 7:00 am to 3:00 pm during peak season.