Propane Combustion in a Gas Grill with Irregular Flameouts I'm troubleshooting a problem with a brand-new propane gas grill that is experiencing flameouts and making puffing/popping sounds.  I'm asking here because I want to understand the basic chemistry that would cause this problem.  

The problem is demonstrated in this video.  

I've already been through all the expected troubleshooting steps:


Replaced the gas regulator
Replaced the burner
Tried three different propane tanks


The grill was purchased about 3 weeks ago. The valve/regulator assembly was replaced last week, and the burner was replaced yesterday, so both parts are essentially new and unused.  

It's hard to tell from the video if the puff causes the flameout or the flameout occurs first, followed by accumulation and detonation of a small amount of unburned propane.

I would like to understand the chemistry principles that govern the combustion of propane in a grill, and what design flaw(s) could cause this behavior.
The brilliance of the orange in flares suggests suggests incomplete combustion of a carbon residue.  This can happen with a poor oxygen mix, but the blue in the core of the flame indicates that mix is fine.  

Also, on the base of the grill there is some charred residue.  

Based on the color, and the residues I expect somewhere in the flow you have some carbon deposits that are occasionally getting dislodged, causing the sputtering.