Burping Heater

My 3600RL with a Suburban 42P heater starting "burping" It lights and runs fine then it sounds like an afterburner kicks in for a few seconds. Continues running fine and finishes the cycle. Took the burner apart looks A-OK. Changed propane sources, no difference. Factory guy said take it to a "Suburban factory dealer" but wouldnt tell me where that was. Im staying in the Tampa area now.
Any help would be appreciated
Fowler

Check for any type of foreign material in the burner and the burner chamber, particularly spider nest in the burner and mud daubers nest in the burner chamber. If you pull out the burner, you can run a water hose in the chamber to clean it out. It sounds like it is back firing and burning inside the burner, I would look for blockage in the burner head.

Abbylind,
We full-time in our 2009 BH-3670. Our furnace (since new) has intermittent indigestion as well. It seems to happen more frequently when the selected propane tank has run out and the auto-changeover regulator has actuated and the red indicator has popped up. This might suggest a propane pressure drop, as I understand that there is a reduction of capacity in this configuration. I have mud-dauber screens installed and have checked for obstructions etc. I also seem notice it more often after the furnace has been running for a few minutes. I have also thought that there may be an issue with condensation at the orifice, as damp combustion air passes through.

I haven't solved the issue, but it also has not caused any detectable problems. I also note that I have heard many neighbors furnaces making the same rumbling noises.

Sorry I can't offer any other insight, except that our rig does this too. Maybe someone else has experienced or fixed this annoyance and will share their remedy.