I recently began burning UAE buck instead of UAE rice in my DF 520. Since the switch and adjusting feed/air settings, my short feed pipe is always hot and I'm getting some fumes back through the hopper. I know that with my short auger pipe it will be slightly warm, but I can't seem to keep it from overheating and getting slight sulfur smell. Looking through the threads with others burning buck most have to up the air, but not the case for me. Why would that be different in my case? Looking for some ideas or suggestions...
Here's the details:
aquastat settings 200-high 160-low 10-differential
timer 1 minute every 1/2 hour
feed rate 4, air 4.25 (2" ash ring & no unburt coal) ( rice setting were feed rate 5, air 4.5 and feed pipe was cool or slighly warm)
draft over fire .02, flue .04 set with dwyer air meter
8" feed pipe into 55gal hopper with cover
when house calls for heat the recovery time is between 45min to 1.5 hours
heating 1800sq ft 2.5 story single home and DHW, single zone, 11 cast iron radiators, all dual-pane windows, keeping house at 69-70 degrees.