Converting a griddle to natural gas

Why it is not a hose swap

Propane and natural gas are different fuels delivered at different pressures with different energy densities. A burner is tuned for one of them through its orifice — a precisely sized hole metering gas flow — and its regulator.

Natural gas has lower energy per unit volume and arrives at lower pressure, so a natural gas burner needs a larger orifice to pass enough fuel. Run natural gas through propane-sized orifices and you get a weak, yellow, low-output flame. Run propane through natural gas orifices and you over-fuel the burner, producing dangerous over-firing and significant carbon monoxide.

That second direction is the genuinely hazardous one, and it is why this is not a DIY improvisation.

What a proper conversion involves

1. A manufacturer conversion kit for your exact model — correctly sized orifices for every burner plus the right regulator.
2. Replacing every orifice, not just the regulator. This is the step people skip and it is the one that matters.
3. A natural gas supply point at the griddle’s location, which usually means a plumber and a permanent gas line.
4. A leak test on every connection before first use.

The honest answer for most griddles

Buy the natural gas version instead of converting a propane one.

Several manufacturers sell natural gas variants from the factory — Weber lists natural gas Slate models alongside the liquid propane ones. A factory NG unit is correctly orificed, correctly regulated, certified as sold and under warranty.

A converted unit is frequently out of warranty the moment you convert it, because the manufacturer certified the appliance with the components it shipped with. Check that before buying a propane griddle you intend to convert — it is often the detail that makes the decision.

What you gain, and what you give up

Gain: no tanks to refill, no running out mid-cook, and a lower running cost where natural gas is cheaper per unit energy than bottled propane.

Give up: portability, permanently. A natural gas griddle is plumbed where it stands. If you ever move it, or move house, it becomes a different project.

You may also give up a little output. Manufacturers sometimes rate the natural gas version of an appliance slightly lower, so check the NG model’s own BTU figure rather than assuming it matches the propane one — which matters per square inch.

Three things not to do

• Do not drill out propane orifices. Orifice sizing is precise. “A bit bigger” is not a specification.
• Do not use a generic conversion kit not listed for your model.
• Do not connect an appliance to a gas line without a leak test. Soapy water on every joint, every time.

If any of that feels beyond you, that is the correct conclusion rather than a reason to press on. Gas work has a failure mode that other appliance work does not.