I have self-installed a Tarm Solo Plus 40 wood gassification boiler and am looking for advice on achieving the proper flue gas temperature. The instructions indicate that flue gas (with a Condor probe thermometer) should be 600F or more. This suggests that 600F is probably optimum for maximum efficiency, as higher temperatures would mean wasted heat up the chimney. I am burning pine (white, red and jack) slab wood, simply because that is the wood I have. It is dried to 10-15% as shown by a moisture meter. Burns typically are reaching flue temperatures of 800-900F and then gradually settle down as the wood is consumed. I have restricted the draft fan damper to the maximum permitted by its adjustment. I also have installed a motor speed control on the draft fan and slowed it down in order to prevent burn temperatures from going higher. I have long burn times, as I am using about 800 gallons of water storage with a plate heat exchanger off the boiler. I do not have turbulators on the boiler heat exchanger tubes. Your ideas and experience will be appreciated.