Just guessing I would say that he has the vacume switch messed up since you say it won't start. The Mt Vernon I just sold wasn't picky at with the vacume switch you could open it for short periods of time without triggering it. My Countryside Magnum isn't very picky with the vacume switch either I can open the door and dry wipe the glass without triggering the switch. The Country pellet stove is another case and is very picky as to the vacume switch, just crack that door and it shuts down so I would assume that any sort of leak or mis adjustment would cause a problem. I would at this time insist on getting a new replacement stove, seems that you have given them plenty of time to figure out and repair the old one.
I burnt a lot corn in the Mt Vernon I had to clean the clinker out twice a day or risk a mis fire if the clinker got to big then come home to a stinky smoked up house, not really smoked up but it had the mis fired odor. I replaced the Mt Vernon with a Countryside Magnum and burn straight corn in it. The Country pellet stove is for supplement heat in a room that is hard to heat due to the layout of the house. I may end up burning some corn in it as the season gets colder but for now I want it to auto light when necessary to break the chill from that room and not cause a cold back draft to the heated rooms during the evening.
I burnt a lot corn in the Mt Vernon I had to clean the clinker out twice a day or risk a mis fire if the clinker got to big then come home to a stinky smoked up house, not really smoked up but it had the mis fired odor. I replaced the Mt Vernon with a Countryside Magnum and burn straight corn in it. The Country pellet stove is for supplement heat in a room that is hard to heat due to the layout of the house. I may end up burning some corn in it as the season gets colder but for now I want it to auto light when necessary to break the chill from that room and not cause a cold back draft to the heated rooms during the evening.