Flame Roll-Out Raypak Heater

[JRHurst00l]

I am having problems with a "flame roll-out" on my Raypak heater. I have cleaned both the burners and the orafices (no buildup or cobwebs) and the heat exchanger (small section of corrosion, but no obstructions). I have found that if I hold a lighter to the end of the gas tube (past the last fin) I can actually cause the flame to "roll out).

Any other ideas on why this keeps happening?

 

[ps0303]

Maybe a pin hole in the manifold. Inspect it very closely and see if the flames is coming out of the manifold tube.