Did I get your attention??? Just reporting that the unit is performing really nice again like when it was new..!!!!!!!!!!
The bottom line was a blocked OAK, the screen outside had such tiny holes that lint created a wall NOT easily visible at least for me until I put my reading glasses and looked really closed...
BTW, burning Stove Chows and so far so good, although they create a little bit of clinker after a couple of days, but man is this unit burning more efficient now..!!
Air, yup that will do it. The good thing about this for you is that you aren't going to spend an arm or leg trying to get it fixed, and you have your stove back!
Glad it was a simple fix. I had a similar issue some years ago.......switched to bigger screen grid, no more problems.