SBB,
I haven't noticed any difference in the surging through the run, but part way through I had to drop the heat due to the low wines turning cloudy/mucky. With the reduced heat, the output of low wines also reduced but still got the surging. I did put my ear down to the outlet but didn't hear any huffing or gurgling. As it doesn't seem to be a common problem and this pot still set up is far from common I'm just going to put it down to the system. I'm doing a stripping run of a grain based wash tonight and will try and keep an eye on the surging to see if it changes at all. Will also prop up the inlet side slightly to make sure the outlet has a clear slope. Going from this pic viewtopic.php?f=17&t=1333&start=80#p17190 there could be a slight bend in the outlet where pooling may be happening. Jacking up the inlet side should sort that out.