Propane delivery noise

If the flame is moving away from the burner the noise will increase.

if your furnace looks like this one in the link every one i have herd sounded like a jet engine its the way they are made something about burner efficiency they draw a lot of air in the combustion process
atwood-dometic furnace

We used our Montana High Country almost every day this last winter at home in the drive way. Our neighbors told us that every time the furnace turned on it sounded like a jet plane taking off. And yes, it did, I must agree. I really took notice of the noise myself after that, but decided to just let it go. I figure, as long as it heats good and works as expected, it can just be noisy. We don't hear it inside, only outside.

Well this ain't my 1st rodeo.

3rd RV in 8 years, my previous RVs had Suburban heaters, 1st time with the Dometic.

And the first thing they will say is, "They all do that."
Standard response.

Well, you answered my question. Sorry, I do not have any ideas - can't hear it.

May be time to tow back to the stealer if that is within reason.

From the inside it's make this very loud noise. It works fine, it's just the noise.

Fan only is fine, it's when the burner kicks in. Same at the end of the heating cycle, when the burner shuts down its quiet...

Are you talking about a roaring out the exhaust pipe? And is the furnace working normal?

I have had one that always sounded like a jet outside and also have heard others like that in a camp ground.

So is the noise inside or outside?

Dometic IS Atwood.....

There is NO adjustment of Gas flow or air flow...both are fixed
Orifice/LP System pressure determine gas flow
Venturi affect of gas flow determines air flow.

Loud Roaring Flame suggests damaged burner or high system pressure

Yep here's the press release.

https://www.dometic.com/en-ca/ca/rebranded/atwood