I have a PG500 and I have never had any issues. Yesterday I was 4 hours into a Boston but and the doors blow open with a boom. I looked inside and the fire pot was flaming, and the blower was on high. I powered off the unit cleaned the pot and restarted. It came back up to 225 but then the temp started going down. Fire pot was not lit so I put it in the oven to complete. I tried to start today, and it feeds pellets but doesn't ignite.