So I have been running the crap out of the defiant 1910 here and we are up almost $210 on the oil bill (how much THEY OWE US). But the other day my wife went to light it off and couldn't get it going. Then I noticed she had let the ash pan fill and had about another inch of ash in there. I cleaned it out an it still didn't want to light off, so I shop vaccummed everything I could find in there to clear it. This worked,but where does the air actually get into the firebox?