If you have time go back and look at my posts from the end of last season. My astoria is really having problems. The best way to describe it is, after start up, every 30 seconds or so here an unusual vibrating noise at which time the combustion air will practically stop creating a lazy fire for a few seconds. Then the air comes right back and is normal till it starts again.. Last season the tech came to look and it was not doing it until right after he left. any ideas?