Atwood 30887 Furnace Orifice #48 NAT | Dometic OEM

The Dometic Atwood 30887 is the #48 natural gas burner orifice for Atwood RV furnaces. It's a small brass jet, but it does one important job. It meters the flow of gas into the burner so the flame lights clean and burns steady. When that orifice gets clogged or damaged, the furnace either won't fire or runs weak and sooty. This is the genuine OEM replacement, sized #48 and drilled for natural gas.

Here's the part that trips people up. This orifice is the NAT version, which means natural gas. That's not the same as LP or propane. Natural gas runs at a lower pressure and carries less energy per cubic foot, so the orifice has to be bored to a different size to deliver the right BTU output. If your Atwood furnace is plumbed to a natural gas supply, say a park-model trailer on a permanent hookup or a unit set up for a natural-gas line, this is your part. If you're running propane out of a bottle or an onboard LP tank like most travel trailers and motorhomes do, you need the LP orifice instead, not this one. Getting the gas type right isn't optional. The wrong orifice throws off the air-to-fuel mix, and that's a combustion problem you don't want in an enclosed space.

Not sure if #48 is your size? Atwood furnaces use different orifice sizes depending on the model and BTU rating, so the safest move is to pull your furnace's parts breakdown or the spec sticker and confirm it calls for the #48 natural gas orifice. Matching the number matters. An orifice that's too large or too small changes how much gas reaches the burner, and that shows up as a flame that's either starved or over-fired.

Why would you be shopping for a burner orifice in the first place? Usually it's a no-heat or low-heat call. The orifice opening is tiny, so it doesn't take much to choke it. Dust, rust flakes off the burner tube, and, believe it or not, spider webs are a classic culprit. Mud daubers and spiders love to nest in the warm, dark burner path over the off-season, and a single web across the jet is enough to starve the flame. If your furnace lights but the flame looks lazy and yellow, or it keeps cycling on the high-limit switch because it isn't burning right, the orifice is one of the first things a tech checks. Sometimes it cleans up. Other times the brass is pitted or someone drilled it out chasing a fix, and then you just replace it.

Keep in mind the orifice is only part of the picture. If your furnace still won't heat after a fresh #48 orifice, look at the gas pressure at the appliance, the sail switch, and the limit switch too. But when the flame is clearly gas-starved and the rest of the furnace checks out, a clean, correctly sized orifice is often the whole fix.

Swapping the orifice is a straightforward job if you're comfortable working around the burner assembly and you shut the gas off first. It threads into the burner, and you'll want the seat clean and the new orifice snugged down so there's no gas leak around the threads. Always leak-check with soapy water after you button it up. If you're not comfortable working on a gas appliance, have an RV tech handle it. It's a cheap part, but it's still gas.

Because this is the genuine Dometic Atwood part, you're getting the exact orifice the furnace was engineered around. No guessing, no reaming out a generic jet and hoping the flame looks right. Atwood's RV furnace line is now part of Dometic, so you'll see both names on these components, but it's the same part you'd get from the original manufacturer. Keep one on the shelf if you camp somewhere with a natural-gas hookup and you count on that furnace through cold nights. A cheap orifice beats a night without heat.