What parts get changed when a fireplace is converted from one gas to the other?
The core parts are the orifices — the drilled jets that meter gas — plus the pilot orifice, and the regulator or its setting for the new fuel's pressure. Depending on the model, the conversion kit may also include a new regulator spring, an air-shutter adjustment, and sometimes burner or valve components. It's a model-specific kit, not universal parts.
The orifice is the heart of it
If you remember one part, make it the orifice — the precisely drilled jet that meters how much gas reaches the burner. Natural gas is low-pressure and lower-energy, so it needs a bigger hole; propane is high-pressure and energy-dense, so it needs a smaller one. Every fuel conversion swaps the main burner orifice and the pilot orifice to the size that matches the new fuel. Get this single part wrong and the fireplace either over-fires and soots (an NG unit on propane) or starves (an LP unit on natural gas).
The supporting cast
A proper kit is more than jets. Most include a pressure regulator or a regulator spring/setting change, because propane and natural gas run at different manifold pressures — the fireplace has to be dialed to the manufacturer's spec for the new fuel. Many kits add an air-shutter adjustment to fine-tune the fuel-air mix so the flame looks right and burns clean. Some units also call for specific pilot assembly components or a valve setting. The exact contents depend on the make and model, which is why the kit has to be the manufacturer's own for your unit — there's no universal one-size conversion.
Why it's not a parts-store afternoon
Swapping these parts is precise work: the tech installs the kit, then checks manifold pressure with a gauge and verifies a clean, correctly shaped flame with no sooting. Set the pressure wrong or install the incorrect orifice and you've built a soot machine or a carbon-monoxide risk. In North Carolina this is licensed gas work for exactly that reason. We source the right kit for your model, install it, test it, and stand behind it. Not sure your fireplace even has an available kit? Call (828) 545-0525 and we'll check.
Related questions
- What is an orifice in a gas fireplace and why does it matter which fuel I use?
- Do I need a conversion kit specific to my fireplace's brand and model?
- Can I do a gas fireplace fuel conversion myself, or does it need a pro?
- Does a gas fireplace need a regulator, and is it different for propane?
- Can I convert my natural gas fireplace to propane?
- How do I know if my house has natural gas or propane?
Still deciding? Talk to a real installer.
Free assessments across Western North Carolina — no pressure, straight answers.