Loud Water heater when door is closed

[25Twin]

We're doing our first boondocking in our 2013 FC with Atwood water heater and in our 2nd day the red light came on in the water heater switch panel. It is lighting Fine and staying lit too, but I noticed when it is running with the exterior access panel open, it is very quiet and has a good steady flame, but when I close the exterior access panel door within a few seconds it gets very loud and you can see the flame through the sight glass become turbulent. This doesn't seem like how you would want it to work. Is this normal? Any ideas? I'll give Atwood a call tomorrow but thought I'd check here. Nothing came up with the search function.

[25Twin]

I have a video but only seem to be able to attach pictures w my phone...

[25Twin]

Just an update, in case anyone else runs into this. Felt kind of silly not realizing it before as it sounded like the flame was starved for oxygen. I spoke to Atwood and they said it's easy to adjust the shuttle to adjust amount of oxygen, but that it wasn't a problem to run it with the door open to keep it quiet in that moment. Since we were leaving that campground that day and going to one with shore power, I planned to experiment later. Low and behold, the issue was gone at the new campground. The difference was being at sea level where it was quiet instead of at 4000 ft elevation.

[DBinSD]

Glad you were able to troubleshoot it ! Congrats