I've always tried to scrape out the burnpot in my Harman P43 before every refire. I switch to manual once the fire gets going, so the igniter does not cycle. Last week, on a few starts, only the left side would catch and eventually the pellets would push the flame into the ash pan if I didn't keep a close eye on it. Talked it over with a friend and he said he never scrapes his pot before refires. I've gone to this method now and see that the pellets ignite more quickly (for the most part) and all the pellets catch. Would the ash in the burnpot have something to do with this? Is there some insulative property the ash brings to the equation?