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Oil Heat vs. Natural Gas: The Real Cost Comparison for Connecticut Homeowners

Published March 2026 · Price Intelligence · 8 min read

If you have oil heat and are wondering whether to convert to natural gas, you're asking one of the most common and financially significant questions in home energy. The honest answer is that it depends — on your gas line access, conversion costs, current fuel price comparison, and your time horizon. Here's the math, without the utility company spin.

First: Can You Even Convert?

Natural gas is not available everywhere in Connecticut. Roughly 45–50% of Connecticut homes use natural gas for space heating; the rest use oil, propane, or electric. Gas service is delivered by pipeline, and if your property isn't near an existing gas main, conversion may not be possible without significant infrastructure cost — or at all.

Check natural gas availability at your address: Southern Connecticut Gas (Avangrid), Connecticut Natural Gas (Avangrid), and Yankee Gas (Eversource) are the three Connecticut natural gas utilities. Their websites have service territory maps and address lookup tools. If you're on the edge of a service area, getting a quote includes a determination of whether service line extension is required and what it costs.

The Conversion Cost

Gas conversion for an oil-heated home involves several components:

ComponentTypical CostNotes
New gas furnace or boiler$4,000–$8,000Installed; high-efficiency 95 AFUE models
Gas piping and meter installation$0–$2,500+Utility often provides meter; piping from meter to equipment is homeowner cost
Service line from main to property$0–$15,000+Utilities often subsidize first 100 feet; longer runs cost more
Oil tank decommissioning$300–$1,500Above-ground tank removal/cleaning; underground requires more
Flue/chimney modifications$200–$800Gas may require different venting than oil
Total typical range$5,000–$20,000+Lower end: gas main nearby, simple installation; upper end: service line extension required

Annual Operating Cost Comparison

The fuel cost comparison between oil and gas is the variable that drives the decision — and it changes with market conditions. At 2025–2026 Northeast pricing:

FuelPriceBTU/UnitSystem AFUEEffective Cost per MMBTU
Heating oil (No. 2)$3.50/gallon138,500 BTU/gal85%$29.75/MMBTU
Natural gas (CT)$1.60/therm100,000 BTU/therm95%$16.84/MMBTU

At these prices, natural gas delivers heat at roughly 43% lower cost than oil — a significant annual savings for a home using 800 gallons of oil annually (equivalent to about 90 MMBTUs of delivered heat). Annual oil cost at 85 AFUE: approximately $2,940/year. Annual gas cost at equivalent heat output: approximately $1,515/year. Annual savings: approximately $1,425/year.

At $1,425/year in savings and a conversion cost of $8,000 (favorable scenario), payback is about 5.6 years. At $15,000 total conversion cost, payback extends to over 10 years.

Natural gas prices are volatile too. The 43% advantage shown above reflects 2026 pricing. In 2022–2023, when natural gas prices spiked following the European energy crisis, the gap narrowed significantly. Gas is generally cheaper than oil in Connecticut's historical pricing, but the margin varies. Don't assume the current price difference is permanent when making a 10+ year payback decision.

The Case for Staying with Oil

The economic case for oil heat isn't just inertia. Several factors favor the incumbent system:

What Connecticut Incentive Programs Cover

Connecticut's Energize CT programs offer rebates on high-efficiency gas equipment (up to $400 for a 95+ AFUE gas furnace or boiler). Heat pump rebates are substantially higher ($1,500–$3,000+ depending on equipment type). Oil equipment doesn't currently qualify for Energize CT efficiency rebates in most programs.

This incentive structure effectively subsidizes conversion to gas or heat pumps — factor the applicable rebate into your conversion payback calculation when comparing options.

Staying with Oil? Pay Competitive Prices

While you evaluate the conversion question, OilOutpost ensures you're paying competitive market prices — not your dealer's default rack rate.

Get Competing Quotes →

Related: Heating Oil vs. Natural Gas: Should You Convert? A Homeowner's Guide  ·  Oil to Gas Conversion: What It Actually Costs to Switch from Heating Oil