Why Long Island Homeowners Are Switching From Oil to Gas
Long Island has one of the highest concentrations of oil-heated homes in the country. Many of these systems were installed decades ago, and as those boilers age, homeowners face a decision: replace the oil boiler with another oil unit, or make the switch to natural gas.
For the majority of homeowners we work with, converting from oil to natural gas is the better long-term investment. Natural gas is consistently cheaper per BTU than heating oil, gas boilers require less maintenance, and modern high-efficiency condensing gas boilers can reach 95-98% AFUE, compared to the 80-86% range typical of most oil systems. Add in the elimination of oil deliveries, oil tank liability, and the cleaner operation of gas, and the case for conversion is strong.
Oil vs. Gas: Side-by-Side Comparison
Here is how oil and gas compare across the factors that matter most to Long Island homeowners.
| Factor | Oil Heat | Natural Gas |
|---|---|---|
| Annual Fuel Cost (avg. LI home) | $3,000 - $4,500 | $1,800 - $2,800 |
| Boiler Efficiency (AFUE) | 80 - 86% | 90 - 98% |
| Price Stability | Volatile, market-dependent | More stable, regulated |
| Fuel Delivery | Scheduled truck delivery | Continuous pipeline supply |
| Storage Tank Required | Yes (indoor or underground) | No |
| Maintenance Frequency | Annual cleaning + nozzle/filter | Annual inspection (simpler) |
| Environmental Impact | Higher CO2 emissions | Lower emissions per BTU |
| Equipment Lifespan | 15 - 25 years | 15 - 20 years (condensing) |
How Much Will You Save by Switching to Gas?
The savings from an oil-to-gas conversion depend on your home's size, insulation, current oil consumption, and the efficiency of the new gas boiler you choose. That said, the numbers are consistent enough that we can give you a reliable range.
For an average Long Island home spending $3,500 per year on heating oil, a conversion to a 95% AFUE gas boiler typically brings annual fuel costs down to $2,000 to $2,500. That is $1,000 to $1,500 in savings every year, which means the conversion often pays for itself within 5 to 8 years through fuel savings alone.
These savings compound over time, especially because gas prices have historically been more stable than oil. You also eliminate oil delivery fees, tank insurance, and the annual burner cleaning that oil systems require.
What Does an Oil-to-Gas Conversion Cost on Long Island?
Typical Conversion Cost Ranges (Installed)
*National Grid often runs the gas line from the street to your meter at no cost. Interior piping from the meter to the boiler is the homeowner's responsibility. Prices include equipment, labor, permits, and standard installation. We provide detailed written estimates before work begins.
The total project cost for a complete oil-to-gas conversion, including the new boiler, gas piping, and oil tank removal, typically falls between $7,000 and $15,000. The wide range reflects the difference between a straightforward swap (gas already at the street, above-ground oil tank, existing chimney compatible) and a more complex job (gas line extension needed, underground tank, chimney reline required).
For a detailed breakdown by boiler type, visit our complete cost guide.
The Complete Conversion Process: Step by Step
An oil-to-gas conversion involves several coordinated steps. Here is exactly how we handle the project from first call to final inspection.
Free In-Home Assessment
We evaluate your current oil system, inspect the basement layout, check chimney condition, and determine gas availability on your street. You will get a detailed written estimate covering every component of the conversion.
National Grid Coordination
If you do not already have a gas line, we coordinate with National Grid to get natural gas service run to your home. National Grid typically installs the line from the street main to your meter at no cost. This process can take 2 to 6 weeks depending on demand and scheduling.
Permits and Approvals
We pull all required permits from your local municipality. Gas work on Long Island requires specific plumbing and mechanical permits, and the installation must pass inspection. We handle all of this for you.
Oil Boiler Removal
On installation day, we disconnect and remove your old oil boiler. We drain the oil lines and cap them properly. The old unit is hauled away and disposed of responsibly.
Gas Piping Installation
We run new gas piping from the meter location to the boiler room. All gas piping is pressure-tested before connection to verify there are no leaks. This work is performed by our licensed plumbers to code.
New Gas Boiler Installation
We install the new gas boiler, connect it to your existing heating distribution system (baseboard, radiators, or radiant floor), set up the venting (chimney or direct vent depending on the model), and wire the controls and thermostat.
Oil Tank Decommissioning
We coordinate the removal or decommissioning of your oil tank. Above-ground tanks are drained and removed. Underground tanks require pumping, cleaning, and either removal or filling with sand by a licensed environmental contractor.
Testing, Inspection, and Walkthrough
We fire up the system, test every zone, verify gas pressure and combustion efficiency, and schedule the municipal inspection. Before we leave, we walk you through the new system's operation and make sure you are comfortable with everything.
Most conversions are completed in 1 to 2 days of on-site work once the gas line is in place. The full timeline from first call to heat running is typically 3 to 8 weeks, depending on National Grid's scheduling for the gas line installation.
Benefits of Converting From Oil to Gas
Lower Fuel Costs
Natural gas costs 25-40% less than heating oil per BTU on Long Island. Those savings add up to $1,000 to $1,500 per year for the average home.
No More Oil Deliveries
No scheduling deliveries, no running out during a cold snap, no price spikes when demand surges. Gas flows continuously through the pipeline to your home.
Less Maintenance
Gas boilers do not require annual nozzle and filter changes, burner cleanings, or soot removal. Annual inspections are simpler and less expensive.
Eliminate Tank Liability
Underground oil tanks are an environmental liability. Leaks can contaminate soil and groundwater, leading to costly remediation. Converting to gas removes this risk entirely.
Cleaner Burning
Natural gas produces roughly 27% less CO2 than heating oil per BTU. No soot, no oil odor in the basement, and no risk of oil spills during delivery.
Increases Home Value
Homes with natural gas heat are more attractive to Long Island buyers. Gas heat is a selling point that can recoup much of the conversion investment when you sell.
Is Natural Gas Available on Your Street?
National Grid provides natural gas service across most of Long Island. Gas availability is generally strong in densely populated areas of Nassau County and western Suffolk County. Some parts of eastern Suffolk and more rural areas may not have gas mains on every street.
The easiest way to check is to call National Grid directly or contact us. We can determine gas availability for your specific address and, if a new gas main extension is needed, we will let you know what that process looks like and how long it typically takes.
If gas is already on your street but your home is not connected, National Grid will typically install the service line from the street main to your meter at no cost. You are responsible for the gas piping inside your home from the meter to the boiler, which we install as part of the conversion.
What Happens to Your Oil Tank?
Once you convert to gas, your oil tank is no longer needed. How it is handled depends on the type of tank.
Above-Ground Tanks (Indoor or Outdoor)
Above-ground tanks are the simpler scenario. We drain any remaining oil (which can typically be sold back to your oil company or pumped out), disconnect the supply lines, and remove the tank from your property. This is usually included in or added to the conversion project at a cost of $500 to $1,000.
Underground Tanks
Underground oil tanks require more careful handling. New York State regulations require that buried tanks be either properly removed or decommissioned in place. Removal involves excavating the tank, pumping out any remaining product, and testing the surrounding soil for contamination. If the tank is in good condition with no evidence of leaks, it can sometimes be decommissioned in place by filling it with sand or foam. This work must be performed by a licensed environmental contractor and typically costs $1,500 to $3,500.
We coordinate with reputable tank removal contractors and can include this work in your overall project estimate so you get one clear price for the entire conversion.
Rebates and Incentives
National Grid and PSEG Long Island offer rebates for high-efficiency gas boiler installations that can significantly reduce your out-of-pocket cost. Federal tax credits under the Inflation Reduction Act may also apply for qualifying equipment. We help identify every rebate and incentive you are eligible for and handle the paperwork on your behalf.
Visit our rebates and incentives page for current program details, or ask us during your free estimate. We can also discuss financing options to make the conversion more manageable.
Chimney and Venting Considerations
Your existing chimney was designed for oil combustion exhaust, which is hotter than the exhaust from a high-efficiency gas boiler. When installing a condensing gas boiler (95%+ AFUE), the exhaust temperature is low enough that it can cause condensation inside an unlined masonry chimney, leading to deterioration over time.
There are two common venting solutions for gas conversions on Long Island. A stainless steel chimney liner can be installed inside your existing chimney to handle the lower-temperature exhaust from a condensing boiler. This typically costs $800 to $2,500 depending on chimney height and condition. Alternatively, many high-efficiency gas boilers can be direct-vented through the wall using PVC piping, which eliminates the chimney from the equation entirely. We will assess your specific situation during the estimate and recommend the most practical option.
Best Gas Boilers for Oil-to-Gas Conversions
When converting from oil to gas, the boiler you choose matters. Here are the brands and models we most commonly recommend for Long Island conversions.
Navien NCB-E Series is a popular choice for conversions because it is a wall-mounted combi boiler that provides both space heating and domestic hot water, freeing up significant basement space once the oil tank and old boiler are removed. It runs at up to 95% AFUE and qualifies for rebates.
Weil-McLain ECO is a compact, high-efficiency wall-hung boiler that works well in tight basement spaces. It reaches 95% AFUE and is known for reliability and quiet operation. It is one of the most commonly installed conversion boilers on Long Island.
Burnham Alpine offers a floor-standing high-efficiency option for homeowners who prefer a more traditional installation style. It is available in a range of sizes to match different home heating loads and achieves 95% AFUE.
Bosch Greenstar is another strong condensing option with a compact footprint. It can be wall-mounted or floor-standing and offers both heating-only and combi models.
We carry and install all major brands. During your free estimate, we will recommend the best boiler for your home's specific heating requirements, budget, and hot water needs. Visit our brands page for more details on each manufacturer.
How Long Does the Conversion Take?
The timeline for a complete oil-to-gas conversion depends on a few factors, primarily whether natural gas is already available at your property and whether National Grid needs to install a new service line.
If gas is already at the meter and ready to go, the actual conversion work (removing the old oil boiler, running gas piping, installing the new boiler, and testing) takes 1 to 2 days. If National Grid needs to run a new gas line to your home, that process adds 2 to 6 weeks to the timeline, depending on their scheduling backlog. We coordinate this process and keep you informed at every step.
The best time to start a conversion is in the spring or summer, when demand for National Grid installations is lower and you are not relying on your heating system. Planning ahead means everything is ready to go well before the first cold day of fall.
Is an Oil-to-Gas Conversion Right for You?
An oil-to-gas conversion is typically the right move if natural gas is available on your street and your oil boiler is reaching the end of its lifespan (15+ years). It also makes strong financial sense if you are spending $3,000 or more per year on heating oil, your oil tank is aging and needs replacement, or you simply want a cleaner, lower-maintenance heating system.
If your oil boiler is relatively new and performing well, it may make more sense to wait until it reaches the end of its useful life before investing in a conversion. And if gas is not available on your street, the cost of a gas main extension may change the math. We will always give you an honest assessment of whether conversion makes sense for your specific situation.
Not sure if conversion is right for you? Our repair vs. replace guide can help you evaluate your options.