You cannot convert most natural gas appliances to propane with a kit alone
A conversion kit — a set of replacement orifices, regulators, and fittings — can make some natural gas appliances run on propane, but only certain models, and only if the appliance was designed with conversion in mind. The manufacturer must have tested and approved the conversion, and the kit must match your exact appliance model. Buying a generic kit and installing it yourself on an unapproved appliance creates a fire and carbon monoxide risk that no amount of caution can eliminate.
The core problem is that natural gas and propane burn at different rates and pressures. Natural gas flows at about 3.5 inches of water column pressure; propane at 10 to 11 inches. The orifice — the tiny hole that meters fuel into the burner — is sized for one fuel only. Swap the orifice without adjusting the regulator and air intake, and you get either incomplete combustion (carbon monoxide) or flame that shoots outside the burner (fire). A kit addresses this, but only if it was engineered for your specific appliance.
Key Takeaways
- Conversion kits work only on appliances the manufacturer explicitly approved for conversion, which you can confirm by checking the model number against the kit documentation or contacting the manufacturer directly.
- A kit typically includes replacement orifices, a regulator, and fittings, but installation requires turning off the gas supply, removing burner components, and reassembling them — a task that demands precision and is not reversible without another kit.
- If no approved kit exists for your appliance, you cannot safely convert it; your options are to replace the appliance with a propane model or continue using natural gas.
- Propane appliances cost more upfront than natural gas models but may cost less per unit of heat in areas where propane is cheaper than piped natural gas.
Which appliances can be converted and which cannot
Cooktops, ovens, water heaters, and furnaces are the appliances most often sold with conversion kits available. Manufacturers like Bosch, GE, and Whirlpool sometimes publish conversion kits for their ranges and cooktops, and water heater makers like Rheem and A.O. Smith do the same. Furnace manufacturers less commonly offer kits, but some regional brands do. The first step is to locate your appliance's model number — usually on a sticker inside the oven, under the cooktop, or on the furnace itself — and search the manufacturer's website or call their customer service line to ask whether a conversion kit exists.
Portable heaters, grills, and older appliances (more than 15 years old) rarely have kits available. If the manufacturer has gone out of business or no longer supports the model, a kit will not exist. In those cases, conversion is not a safe option. Some people attempt to use universal kits sold online, but these are not tested against specific appliances and create real hazards. A universal kit cannot account for the exact burner design, air shutter position, or regulator sensitivity of your model.
What a conversion kit contains and how installation works
A typical kit includes replacement orifices (the small brass pieces with different hole sizes), a propane regulator, inlet fittings, and sometimes a new air shutter or baffle. The kit documentation will specify which parts go where. Installation involves shutting off the gas supply, disconnecting the appliance from the gas line, removing the burner caps and grates, unbolting the burner heads or cooktop assembly, and swapping out the orifices and regulator according to the instructions. The process takes one to three hours for a cooktop or range, longer for a furnace.
Precision matters. Orifices must be seated fully and evenly; a regulator must be oriented correctly; fittings must be hand-tightened and then turned with a wrench to the exact torque specified in the kit instructions. If you over-tighten, you crack the fitting. If you under-tighten, gas leaks. After reassembly, you must test for leaks using soapy water — never a flame — and verify that the burner flame is blue and steady, not yellow or orange. If you are not comfortable with this level of precision, hire a licensed gas technician to do the work. The cost of a technician visit (typically $150 to $300) is worth the safety assurance.
Cost comparison: conversion kit versus buying a propane appliance
A conversion kit for a cooktop or range costs between $50 and $150, depending on the brand and model. A water heater kit runs $30 to $80. Labor to install it, if you hire a technician, adds $150 to $300. By contrast, buying a new propane cooktop costs $400 to $1,500; a propane water heater, $600 to $1,500. If your current appliance is relatively new and works well, a kit makes financial sense. If the appliance is old or failing, replacement may be the better choice.
The long-term fuel cost also matters. In areas where propane is significantly cheaper than natural gas per BTU, a propane appliance will save money over time. In areas where natural gas is cheaper, the opposite is true. Check local propane and natural gas prices with a few suppliers in your area to compare. Propane is often cheaper in rural areas without natural gas pipelines; natural gas is usually cheaper in urban and suburban areas with established distribution networks.
Safety concerns and why DIY conversion is risky
The two main hazards are incomplete combustion (which produces carbon monoxide) and flame escape (which can ignite nearby materials). Both occur when the fuel-to-air ratio is wrong. A misaligned orifice, an incorrectly installed regulator, or an air shutter left in the natural gas position will cause one or both. Carbon monoxide is odorless and colorless; you cannot detect it without a detector. Flame escape is visible but can happen suddenly if the burner is bumped or if debris clogs the orifice.
A licensed technician has the tools to measure flame color and heat output, and the experience to spot installation errors before they become hazards. If you convert the appliance yourself and something goes wrong, your homeowner's insurance may not cover damage or injury. Some insurance policies explicitly exclude claims related to DIY gas appliance work. A technician's work typically comes with a warranty and documentation that satisfies insurance requirements.
How to find the right conversion kit for your appliance
Start with the manufacturer's website. Search for your model number plus "conversion kit" or "propane kit." If the manufacturer has a kit, they will list it with a part number and a link to buy it or a list of authorized retailers. If the website search yields nothing, call the manufacturer's customer service line — the number is usually on the appliance or in the original manual. Have your model number ready. Ask whether a kit exists, whether it is still in production, and where to buy it.
If the manufacturer confirms no kit exists, do not buy a generic or universal kit. Instead, consider whether you can replace the appliance with a propane model, or whether you can continue using natural gas if it is available in your area. If you must convert and no kit is available, a licensed HVAC or appliance technician may be able to modify the appliance safely, though this is rare and will be expensive. Most technicians will decline to do custom conversions because the liability is too high.
Propane supply and storage considerations
Before you convert, confirm that propane is available in your area and that you have a way to store and refill it. If you live in a house, you will need a propane tank — typically 100 to 500 gallons — installed outside and connected to the appliance with a copper or steel line. Tank installation costs $500 to $2,000 depending on size and site conditions. If you rent or live in an apartment, your landlord may not allow a tank, or the building may not have space for one. Check your lease and ask your landlord before you buy a kit.
Propane tanks require annual inspection and maintenance. You must arrange refills when the tank runs low, which in winter can mean frequent trips if you heat with propane. Some suppliers offer automatic delivery, which costs more but eliminates the need to monitor the tank yourself. Factor these logistics into your decision. If the hassle of tank management outweighs the fuel savings, natural gas may be the better choice even if propane is cheaper per unit.
Frequently Asked Questions
Can I convert a natural gas furnace to propane myself?
Only if the manufacturer offers an approved conversion kit for your exact model and you are comfortable with precision mechanical work. Furnace conversions are more complex than cooktop conversions because they involve the burner assembly, the regulator, and sometimes the air intake. If you are unsure, hire a licensed HVAC technician. A furnace that is not converted correctly can produce carbon monoxide, which is life-threatening.
What if I convert the appliance and then want to switch back to natural gas?
You will need a second kit designed to convert the appliance back to natural gas. Not all manufacturers make reverse kits. Before you convert, confirm that a reverse kit exists and is available. If it does not, converting is a one-way change.
Will my homeowner's insurance cover a DIY conversion?
Most policies do not cover damage or injury resulting from DIY gas appliance work. Check your policy or call your agent before you start. If you hire a licensed technician, the work is usually covered and may even lower your liability risk in the insurer's eyes.
How do I know if the conversion kit I bought is the right one?
The kit documentation must list your appliance's exact model number. If your model number is not listed, do not install the kit. Contact the kit manufacturer or the appliance manufacturer to confirm compatibility before you open the box.
Is propane more expensive than natural gas?
It varies by region and season. In rural areas without natural gas pipelines, propane is often cheaper. In urban areas with established gas lines, natural gas is usually cheaper. Check current prices with local suppliers to compare the cost per BTU in your area.