The easiest way to solve a problem yourself is to ask someone else the question. Well, my flue temp problem is solved, and the solution came to me in my sleep last night. The Tarm draft fan has a damper with an adjustable stop. I had adjusted the stop all the way down so that the damper would open the least, and still I had high flue temp. Based on my sleep solution, I took another look at the draft fan damper this morning and found that I could adjust the damper stop lever so that the adjustable stop would close the damper even further. With this done and a little time to adjust the stop with the boiler operating, flue temp only rose to 700 on a fresh charge of pine and then settled down to 600-650 for a long burn. 600 is what Tarm recommends. Gassification was just purring - a real beauty. I may tinker a little more to drop the temp into the 500-600 range and check results. For any others, be aware that the Tarm may be delivered with a mis-adjusted draft fan damper lever. I assumed that the damper lever was where it was supposed to be, and obviously with my very good chimney draft, this was not the case. In all events, an easy user solution. With 3-1/2 months of operation and burning only pine, my chimney still is practically new-shiny clean, and there is a small accumulation of ash dust at the bottom of the elbow where the flue exits the boiler. I do not anticipate any creosote problem this burning season. BTW, -16F last night.