Hi, I recently picked up a used Big E - hadn't been used much. I fired it up about 10 days ago and set it at #4 to get my shop up to a comfortable warmth level. All was well, but flame started getting very lazy, so I shut it down and cleaned it yesterday - including combustion motor and fins and airway. So I fired it back up and set it at #3 - nice bright flame, but after 30 minutes it went out with #2 flashing light. Checked airline and air hole into stove and fired it back up. Same thing - 30 minutes or so and it would go out and flash #2. So, I had no idea what the deal was - ran fine until I cleaned it. I unplugged it from wall, then back in and refired it up at setting #2. It ran all night fine. So this morning, I bumped it up to setting #3 and went to work. Had to come home a bit ago (hour and a half later) and sure enough, it's out again with #2 light flashing. I just re-fired it back up at #2, but any idea why it suddenly won't run any higher then #2? Thanks in advance.