Cost to Convert a Furnace From Propane to Natural Gas

Converting a furnace from propane to natural gas involves several cost variables and decisions. This article outlines typical price ranges, factors that drive expense, required parts and labor, permitting and safety considerations, and how to evaluate long-term savings. Accurate budgeting and understanding local code requirements can prevent surprises.

Item	Typical Cost Range (USD)
Licensed Conversion Kit (if available)	$100 – $400
Gas Line Installation (per linear foot)	$15 – $50
Permit & Inspection	$50 – $300
Labor (total)	$300 – $1,200
Full Conversion Including Piping	$800 – $3,500+

Why Convert From Propane To Natural Gas

Natural gas is often less expensive per therm than propane, and many homeowners switch to reduce monthly fuel costs and eliminate propane tank delivery logistics. Natural gas may also produce lower carbon dioxide emissions per unit of energy than propane, offering an environmental benefit. The feasibility depends on the availability of a municipal natural gas main, the furnace model, and local code requirements.

Key Factors That Affect Conversion Cost

Several variables determine the overall price: furnace compatibility, availability and distance to the natural gas main, local labor rates, permit fees, and whether a conversion kit exists for the furnace model. Unforeseen issues such as access problems or required replacement parts also increase cost.

Furnace Compatibility

Some furnaces are convertible with a manufacturer-approved conversion kit, which simplifies the process and keeps the warranty intact. Other units require significant modification or full replacement. The cost difference between conversion and replacement can be substantial.

Distance To Gas Main And Gas Line Complexity

Running a new gas line from the street to the house or from the meter to the furnace is often the largest variable cost. Trenching, boring under driveways, or navigating structural obstacles increases labor and materials costs.

Local Labor And Material Prices

Labor rates vary across regions; metropolitan areas typically report higher hourly rates. Material prices for black iron pipe, CSST, fittings, and regulators also influence the final quote.

Permits, Inspections, And Code Compliance

Most jurisdictions require permits and an inspection for gas line work and fuel conversion. Code-related upgrades such as venting modifications, carbon monoxide detectors, or clearance changes can add to the cost.

Typical Cost Breakdown

The following outlines common cost components homeowners will encounter when converting a furnace.

• Conversion Kit: If the furnace manufacturer offers a kit, it typically costs $100–$400 and includes orifices, a pressure regulator, and instructions.
• Gas Line Materials: Black iron pipe or CSST ranges from $2 to $10 per foot for materials; installed cost per foot often falls between $15 and $50 including labor.
• Labor: Technicians charge either hourly ($50–$150/hr) or a flat rate; typical total labor runs $300–$1,200 depending on complexity.
• Permits and Inspection: Fees usually range from $50 to $300 but vary by municipality.
• Additional Parts: New regulators, pressure testing equipment, venting modifications, and safety devices may add $100–$600.

Conversion Versus Replacement: When Replacement Makes Sense

When furnaces are old, inefficient, or not convertible, replacement may be the more economical long-term choice. New high-efficiency natural gas furnaces can reduce fuel use and often qualify for rebates. If the cost of bringing a gas line plus conversion approaches the price of a new furnace and installation, replacement should be considered.

Step-By-Step Conversion Process

The following summarizes standard steps a licensed professional typically performs during conversion to ensure safety and compliance.

1. Confirm natural gas availability and obtain quotes for gas service extension if needed.
2. Verify furnace model compatibility and order a manufacturer-approved conversion kit if available.
3. Pull permits and schedule inspections per local code.
4. Install or route gas piping from meter to furnace location, including shutoff valves and testing ports.
5. Install conversion components: orifices, regulators, and adjust burners per manufacturer instructions.
6. Perform pressure and leak testing, verify combustion performance, and adjust draft/venting as required.
7. Complete final inspection and documentation for the permit.

Permits, Safety, And Code Considerations

Permits and inspections are critical for gas conversions. A certified technician must perform pressure testing, check for CO, and ensure correct manifold pressure. Attempting DIY gas conversions is risky and often illegal; it can void warranties and insurance coverage.

Expected Timeline

Simple in-house conversions where a gas main exists can take 2–8 hours. If a new gas service from the street is required, the project may take several days to weeks depending on utility scheduling and permit processing. Unexpected delays can arise from weather, trenching challenges, or supply lead times.

How To Get Accurate Estimates

Obtain at least three written quotes from licensed HVAC or plumbing contractors. Ask each for a line-item estimate showing materials, labor, permit fees, and testing. Verify contractor licensing, insurance, and references. Confirm that the quoted work includes code-compliant testing and final inspection documentation.

Financing, Rebates, And Incentives

Many utilities and state programs offer rebates for high-efficiency natural gas equipment. Federal tax incentives for energy efficiency may apply in certain circumstances. Financing options such as HVAC loans or home improvement loans can spread costs over time. Homeowners should check local utility websites for rebates and consult a tax professional for incentive eligibility.

Estimated ROI And Fuel Cost Savings

Savings depend on local fuel prices and furnace efficiency. Natural gas typically costs less per BTU than propane, so conversion can lower monthly heating bills. Homeowners should compare current propane bills to projected natural gas costs using local utility rates and expected furnace efficiency to estimate payback time.

Common Questions

Is My Furnace Convertible?

Manufacturer documentation and the model/serial number will indicate if a certified conversion kit is available. If documentation is not accessible, a licensed technician can determine convertibility.

Will Conversion Affect Furnace Warranty?

Using a manufacturer-approved conversion kit and licensed installation usually preserves the warranty. Improper or DIY conversions can void warranties and homeowners insurance coverage.

How Much Will Gas Company Charges Be To Extend Service?

Gas utilities have varied policies: some offer credits or free extensions in subdivisions, while others bill the homeowner for main extension costs. Contact the local gas provider for a written estimate of service connection costs.

Tips To Minimize Conversion Costs

• Get multiple bids from licensed contractors to compare pricing and scope.
• Bundle upgrades (like a new high-efficiency furnace) to qualify for rebates and lower per-unit labor costs.
• Schedule work during off-peak seasons for potential discounts or faster scheduling.
• Confirm what the quotes include—testing, permits, meter work, and cleanup—to avoid surprise add-ons.

When To Call A Professional

Any work involving fuel gas lines, pressure regulators, or burner adjustments should be handled by a licensed HVAC or plumbing professional. Safety risks include gas leaks, fires, explosions, and carbon monoxide exposure. Professional installers also ensure compliance with local codes and proper documentation for permits and insurance.

Resources And Next Steps

Homeowners should contact the local natural gas utility to confirm service availability, obtain any utility-side quotes, and learn about incentives. It is advisable to gather manufacturer information for the current furnace, request written estimates from licensed contractors, and verify permit requirements with the local building department. Accurate planning reduces cost uncertainty and ensures a safe, code-compliant conversion.