Oil to Gas Conversion: What It Actually Costs to Switch from Heating Oil

April 3, 2026 • 12 min read • Money & Planning

Every few years, heating oil prices spike and homeowners across the Northeast start asking the same question: should I just switch to gas? It seems simple — natural gas is usually cheaper per BTU, and the gas company will happily come out and give you an estimate. But the total cost of conversion surprises most people. Here's the complete, realistic picture.

First: Is Natural Gas Even Available at Your Address?

This is the question to answer before everything else. Natural gas is only available in areas served by a gas distribution main — and in much of rural Connecticut, Massachusetts, and the broader Northeast, those mains simply don't run down your road. You can check availability by calling your regional gas utility (Eversource Gas, Avangrid/Southern Connecticut Gas, National Grid) or by entering your address on their website.

If gas isn't available at your property, your options are propane (which often costs more than oil per BTU and requires a tank on your property) or a heat pump (which deserves its own article — see our heating oil vs. heat pump comparison). For the rest of this article, we'll assume gas service is available at your address.

The Full Cost of Conversion

Gas conversion costs fall into three categories: utility connection fees, new equipment inside your home, and the removal or decommissioning of your oil system. Most estimates you see online focus only on the equipment — and consistently understate the real total.

Cost Item	Typical Range	Notes
Gas company connection fee	$500–$3,000+	Depends on how far the main is from your house. Some utilities waive or discount if many neighbors convert at once.
Gas meter installation	Usually included by utility	The utility installs the meter; you pay to run the line inside.
Interior gas line installation	$500–$2,000	Running pipe from meter to furnace/water heater location. More if running to multiple appliances (stove, dryer).
New gas furnace or boiler	$3,000–$7,000 installed	High-efficiency (95%+ AFUE) gas furnaces cost more upfront but qualify for rebates and pay back faster.
Oil tank removal/abandonment	$500–$1,500 (above-ground) / $1,000–$3,000 (underground)	Above-ground tanks are straightforward. Underground tanks require environmental assessment — costly if contamination is found.
Oil system decommissioning	$200–$500	Draining and disconnecting oil lines, furnace removal.
Permits and inspections	$200–$800	Required in most CT/MA towns. Include in your contractor budget.
Total estimated range	$5,500–$14,000+	Underground tank, far-from-main location, or new boiler vs. furnace all push toward the high end.

The underground tank wildcard: If you have an underground oil tank, the cost and complexity of conversion increases significantly. Environmental testing is required, and if contamination is found, remediation can run $10,000–$50,000+. Before committing to any conversion, have your tank assessed by a licensed professional if you don't already know its condition.

Available Rebates and Incentives

Several programs reduce the upfront conversion cost:

CT Energize (Connecticut): Rebates on high-efficiency gas equipment — up to $600 for a high-efficiency gas furnace or boiler through Eversource or UIL Holdings programs. Check energizect.com for current offers.
Mass Save (Massachusetts): Among the most generous utility rebate programs in the country — up to $2,500 for high-efficiency gas heating equipment. Income-eligible households may qualify for zero-interest financing.
Federal tax credit: High-efficiency gas furnaces and boilers (95%+ AFUE) qualify for a 30% federal tax credit under the Inflation Reduction Act, up to $600/year for the equipment cost.
Utility connection incentives: Gas utilities sometimes offer reduced connection fees or free connection within a certain distance if you're in a new service area they're expanding into.

With rebates and the federal credit, a well-timed conversion with a qualifying high-efficiency system can reduce total cost by $2,000–$4,000.

The Payback Calculation

Whether conversion makes financial sense depends on the price spread between gas and oil — which changes constantly. Here's how to run the math for your home:

Find your annual oil usage. Look at your delivery receipts or dealer statements. A typical CT home uses 600–900 gallons per year.
Convert to BTUs. One gallon of heating oil produces about 138,000 BTU of heat (at ~85% efficiency for a standard oil furnace). 700 gallons × 138,000 BTU = 96,600,000 BTU.
Price oil at current rates. At $3.50/gallon: 700 × $3.50 = $2,450/year.
Price the equivalent gas. One therm of natural gas = 100,000 BTU. At 95% efficiency for a modern gas furnace, you need 96,600,000 ÷ (100,000 × 0.95) = ~1,017 therms. At $1.40/therm (a typical CT rate): $1,424/year.
Annual savings: $2,450 − $1,424 = $1,026/year.
Payback period: $8,000 conversion cost ÷ $1,026/year = ~7.8 years.

At current price levels, a mid-range conversion typically pays back in 6–10 years. When oil spikes to $4.50+ (as it did in 2022), payback accelerates to 4–5 years. When oil is at $2.80 (2019 levels), payback can stretch to 15+ years.

The price risk argument: Oil prices are more volatile than gas prices. Gas is priced on North American supply/demand; oil is a global commodity subject to geopolitical shocks. Some homeowners convert simply to reduce exposure to oil price volatility — regardless of where today's prices sit.

When Conversion Makes Sense

Good candidate for conversion

Your oil furnace is 10+ years old and will need replacement soon anyway. Gas service is available at your address. Your oil tank is above-ground and in good condition (easy, clean removal). You plan to stay in the house 10+ years to recoup the investment. The current oil-to-gas price spread is wide.

Borderline — run the numbers carefully

Your oil system is relatively new (less than 5 years old). You're not sure how long you'll stay in the home. Gas availability requires a long line run or high connection fee. Oil prices are currently moderate (under $3.50/gallon).

Probably not worth it right now

You have an underground oil tank in unknown condition (environmental risk). Gas isn't available at your address. Your oil system is new and working well. You're planning to sell the house within 5 years. You're exploring heat pumps as an alternative (they may have a better ROI in your situation).

The Alternative: Stay on Oil and Shop Smarter

Many homeowners decide that the upfront cost and complexity of conversion isn't worth it — especially if their oil system is in good shape. If that's your situation, the best move is simply to stop overpaying for the oil you use.

The typical CT homeowner with a 700-gallon annual usage and a single dealer relationship overpays by $200–$400/year compared to what's available if they shop around. Over 10 years, that's $2,000–$4,000 in unnecessary spending — money that doesn't require a $10,000 conversion to save.

See what dealers are charging in your area

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Bottom Line

Oil-to-gas conversion is a legitimate financial move for many Northeast homeowners — but the all-in cost of $6,000–$14,000 means you need to stay in the house long enough to recoup it. Run your own numbers using the BTU formula above, get quotes from at least two HVAC contractors, check current rebate programs, and honestly assess your oil tank situation before committing.

If the math works in your situation, the peace of mind of escaping oil price volatility is real. If it doesn't, optimizing your current oil costs through competitive pricing is money in your pocket starting this winter.