I noticed this problem with what appears to be smoke coming form the auger tube in my 9 yr old Harman P61a recently. here is a short (hopefully) breakdown of what has been going on. Got a new Esp prob last winter, and noticed that now and then it would kick the dist fan off then on when I cleaned the probe while the stove was running. Also, once in a while the probe would seem to read way cooler than it should, and the stove would feed until it maxed out on temp, slack off, then refeed to the max. I would wiggle the wire and would go back to normal. I figued this was no good and got a new probe recently, installed new prob, and now it seems to be running way too cool. On stove temp #5 the flames barely go higher than the flameguide, until the ash builds up. Normally #5 stove temp would be just licking the heat exchangers, and be just where I needed to be in cold weather. Once the ash builds up a bit it burns way hotter, I measure with a IR heat gun at the front centre of stove by heat exchangers. I also notice that until the ash builds up I get a taller lazier flame on one side of burnpot. Replaced ashbin door gasket, glass door gaskets seem fine. Sooo... To get to the topic of my post, while changing probes I turned stove off, let cool down, then unplugged, fire was not out, but nearly. while I was changing probes, I noticed a small stream of smoke coming up centre between hopper and firebox. looking between the hopper and firebox it appeared to be coming from the auger tube, but I could not tell exactly where. My question is, has anyone heard of any problems like this before, and is it something that could be patched with high temp caulking until the end of the season. I plan on taking it to my trusty Harman dealer for a complete go over this summer. Also I have noticed a slight whistle noise from time to time on startup, couldn't track it down, but I'm sure this smoke thing is it. And, I have a funny feeling it is the cause of the low flame and low heat output until the ash builds up, and the taller lazier flame on one side of burnpot.