HVAC Replacement Cost in Connecticut (2026)

2026 installed cost ranges

Estimates for typical Connecticut homes. Your quote depends on equipment brand, efficiency, ductwork, electrical service, and fuel type.

System	Installed range	Typical lifespan
Gas furnace (80% AFUE)	$4,500–$6,000	15–20 years
Gas furnace (95%+ AFUE)	$5,500–$7,500	15–20 years
Oil furnace	$5,000–$8,000	15–20 years
Central AC	$5,000–$9,000	12–15 years
Gas boiler	$6,000–$9,000	20–30 years
Oil boiler	$7,000–$10,000	20–30 years
Ductless mini-split (whole home)	$10,000–$18,000	12–15 years
Ducted heat pump (whole home)	$8,000–$15,000	12–15 years

What moves the quote: the five levers

1. Efficiency tier

The step from baseline to high efficiency (80%→96% AFUE furnace, 14→18 SEER2 AC) adds roughly $1,000–$2,500. In Connecticut, with our fuel costs, the payback on high efficiency is faster than national averages suggest — but only if you use enough fuel for the savings to accumulate. A vacation home doesn't justify premium efficiency; a primary residence with $3,000/year heating bills does.

2. Ductwork

The most underpriced line item in HVAC quotes. Sealing and insulating existing ducts: $1,500–$4,000. Modifying or extending ductwork: $2,000–$5,000. Full duct replacement: $5,000–$10,000. In pre-1970 CT homes, assume the ducts need attention until a contractor proves otherwise with measurements.

3. Electrical service

Heat pumps, high-efficiency systems, and anything with backup electric heat may need panel upgrades or new circuits: $1,000–$3,000. Homes still on 100-amp service (common in older Hartford County neighborhoods) almost always need the upgrade for a heat pump.

4. Fuel infrastructure

Oil-to-gas: gas line run, chimney liner, oil tank removal — $2,000–$5,000+ beyond the equipment. Chimney liners alone run $1,500–$3,000 and are needed in most older-home boiler/furnace replacements regardless of fuel.

5. Access and complexity

Finished basements, tight crawlspaces, equipment in attics, asbestos abatement, permit fees — the physical realities of your house. Budget 10–15% contingency on any major install in a pre-1960 home.

The repair-vs.-replace decision framework

Work through these in order:

1. How old is it? Past 75% of expected lifespan (furnace 15–20 yrs, AC 12–15, boiler 20–30), lean replace. Under 50%, lean repair.
2. What does the repair cost relative to replacement? Over 50% of replacement cost on an older system → replace. Under 30% on a younger system → repair.
3. How often has it needed service? Two or more calls in two years signals systemic decline. Total your recent repair spending — it's often sobering.
4. What's the efficiency gap? Replacing a 65–70% efficient 30-year-old oil burner with 95% equipment (or a heat pump) cuts fuel use dramatically. Model the payback with current CT fuel prices.
5. Is the refrigerant obsolete? R-22 systems: don't put major money into them, period.
6. Are you staying? If you're selling within 2–3 years, a working repair usually beats a premium replacement for resale math — though a dead system is a negotiation disaster.

Timing: when to buy

• Best prices: shoulder seasons (March–May, September–November) when contractors are between peaks. Emergency January/February replacements cost 10–20% more and limit your negotiating leverage.
• Rebates: Energize CT rebate levels reset periodically — a fall install may catch better incentives than spring, or vice versa. Ask.
• Don't wait for failure on a system past 18 years. Planned replacement in October beats emergency replacement in January on price, selection, and sanity.