Hello all! I’m having a small issue with my Harman insert just installed last Aug. burned about 2ton so far. Now normally when I open the door to scrape the pot /remove ash the distribution slows to about %1 then when I close it , it ramps back up immediately .. Lately when I closed the door the fan takes a while to come up to 100% even ramps up slowly at times. It may now take about 3-4 min. I feel like something is getting dirty or about to break.. where should i be looking to fix this ..