New gas furnaces in Bridgeport, sized by load and vented to code
A new furnace is only as good as its sizing and its ducts. We check both, then install, permit and commission the system.
Gas furnace replacement in Connecticut typically runs about $3,500 to $8,000 installed, depending on efficiency, size, venting and duct condition. In Bridgeport most swaps take one day. We size the furnace with a load calculation, check the ducts and flue, pull the permit and test combustion before we leave.
Updated October 2026
Why the old furnace size is usually the wrong size
Most furnaces coming out of Bridgeport basements are oversized, sometimes by half. An oversized furnace short-cycles, wears out its ignitor and heat exchanger faster and leaves cold rooms at the ends of long duct runs.
We run a room-by-room load calculation and measure the duct system's static pressure before recommending a size. That shows whether a few returns or a trunk section should be fixed at the same time.
What decides the price of a new furnace
Published Connecticut ranges put gas furnace replacement at about $3,500 to $8,000 installed.
Efficiency
A 96 percent condensing furnace costs more than an 80 percent unit and needs new venting.
Staging and blower
Two-stage and variable-speed models add equipment cost.
Duct condition
Undersized or leaking ducts may need repair; duct changes during an install often add $500 to $2,000.
Venting and chimney
A liner for a stranded water heater or a new sidewall vent adds parts and labor.
Access
Tight basements and narrow stairs lengthen removal and setting.
Permit
Connecticut furnace permits typically run $100 to $300.
What a furnace install includes
- Room-by-room load calculation
- Duct static pressure test
- New furnace set on a level pad or platform
- Gas shutoff, sediment trap and leak test
- New venting, chimney liner or sidewall PVC as needed
- Condensate drain or pump on high-efficiency units
- Filter rack and first filter
- Permit, inspection and combustion test
- Removal and disposal of the old furnace
80 Percent vs 96 Percent AFUE
An 80 percent furnace vents up the existing chimney and costs less to buy. A 96 percent condensing furnace wastes far less gas but needs PVC venting through a sidewall or roof and a drain for the condensate. Over a Bridgeport heating season that runs from October into April, the condensing unit usually pays back. If the chimney is shared with a water heater, removing the furnace from it changes the draft, which is why we check that at the same visit. Current Energize CT rebates favor high-efficiency equipment, and we note which models qualify.
Two-Stage and Variable-Speed Models
A single-stage furnace is either fully on or off. A two-stage furnace runs on low fire most of the winter and only goes to high fire on the coldest days, which means longer, quieter, more even cycles. A variable-speed blower adds finer airflow control, better dehumidification with central air, and noticeably lower fan noise. It is worth it in homes with uneven rooms. It is not worth it if the ducts are badly undersized, because the blower will simply run at high speed trying to push air.
Sidewall PVC Venting for High-Efficiency Units
A condensing furnace vents through two PVC pipes, an intake and an exhaust, usually out the side of the house. The termination has to sit clear of windows, doors, the gas meter, the property line and the expected snow level, and it has to be pitched so condensate drains back to the furnace. Bad placement is how these installs fail inspection or ice up in January. We lay out the vent path before the install day and show it to you.
Removal and Disposal of the Old Furnace
Pulling the old furnace includes disconnecting and capping the gas, removing the flue connector, cutting the old unit free of the plenum and carrying it out, which can be the hardest part in a basement with narrow stairs. If the old unit was a converted oil furnace, we also seal any abandoned chimney opening. We protect floors and stair treads on the way out. The old furnace leaves with us, and nothing is left in the yard or the driveway.
Why Bridgeport houses change the approach
Connecticut homes built before 1975 often have undersized or leaking ducts, and in Bridgeport that describes most of the forced-air houses we see. Upgrading the ducts during a furnace job typically adds $1,500 to $5,000, so we measure first and only recommend it where it changes comfort. Permits apply too: towns around here, Milford among them, require a permit and inspection for furnace installs, with fees usually $100 to $300.
We service and install Carrier, Lennox, Trane, Goodman and more
How your furnace replacement runs
- 1
Load calculation
We size the furnace to the house, not to the old nameplate.
- 2
Duct and flue check
Static pressure and the chimney or vent path are measured before quoting.
- 3
Written quote
You get options for efficiency and features with the cost of each.
- 4
Permit filed
We file with the town and schedule the inspection.
- 5
Install day
Old unit out, new unit set, gas, venting, condensate and wiring connected.
- 6
Commission
Gas pressure, temperature rise, combustion and draft are tested with the furnace running.
- 7
Walk-through
You get the filter size, the thermostat settings and the paperwork.
Planning a furnace replacement?
Get a load calculation and a written quote before the first cold snap fills the schedule.
(203) 568-0715Gas Furnace Installation & Replacement questions from Bridgeport homeowners
Repeated repairs, a cracked heat exchanger, rising gas bills and a furnace past about 15 to 20 years are the common reasons.
That comes from a load calculation, not square footage or the old unit. Many existing furnaces are oversized and a smaller one heats more evenly.
In most Bridgeport homes with long heating seasons, yes over its life, but it needs sidewall PVC venting and a drain. We show the payback for your house.
Usually one day for a like-for-like swap. Venting changes or duct work can add a second day.
If it shares the chimney with the old furnace, it may need a liner once the furnace moves to sidewall venting.
Energize CT offers incentives on qualifying high-efficiency equipment. The federal 25C tax credit ended December 31, 2025. We note which models qualify when we quote.
Related jobs we handle
Oil Furnace Installation
New oil furnaces with the burner, flue and tank checked.
Oil Furnace Installation in BridgeportOil-to-Gas Conversion
New gas furnace or boiler, chimney lining and oil tank removal.
More on oil-to-gas conversionComplete HVAC System Replacement
Matched furnace and AC replaced together, ducts checked.
How we handle complete HVAC system replacementGet a furnace sized to your house
Call to book a load calculation and a written replacement quote. We look at the ducts and the venting before we give you a number.