Did you already buy it? If not, can you still get out of the deal?
Funny you ask that... Now that I've done some more research I've connected some dots and I believe I bought my FC1000 a couple months ago from @Mrpelletburner without knowing it. If that's not true, here are some weird coincidences... When I picked up the 1000 from a person in Massachusetts (I know his signature says NH but hear me out) he had used a silver jeep with a winch to remove the unit from basement. At the beginning of this thread he posted a picture of a silver jeep with mass plates and a winch being used to move the unit through the bulkhead. Also in the picture is a 2x4 skid built around the unit for sliding up/down the stairs. This skid is almost identical to the home built skid that he built around the 1000 when I picked it up. Also, the person I bought from had a 1000, a 1500 with a cracked weld, and a brand new 1500, all for sale. Sound familiar?
So why does any of this matter? Because when I asked why he was selling the units he said the company made a mistake selling him the 1000 for his house and he should have been spec'd for a 1500 so he only had to pay the difference to get the 1500 (the part about paying the difference at least aligns with your story). Then he said the 1500 cracked due to a defect so they sent him a new one and he was selling all three to buy a nicer furnace. I had come across these forums months prior when I initially started researching wood furnaces but did not read all the posts in detail, I just assumed one customer had a bad experience due to some chimney issues. When I was there to look at the unit he was telling me how they are solid, well-built units. I mentioned seeing this forum where someone had a bad experience and he said (paraphrasing) "yeah I saw that forum, he had trouble because they told him to install a barometric damper, definitely don't do that and you'll be all set." Why not just tell the truth about the struggles and offer some advice? Not even a warning?
So shame on me for believing someone on craigslist (I really know better) and for not doing more research... I initially wasn't planning on installing one until next year but my HVAC guy said if I got one right away he would nicely tie it into the ductwork for no extra charge so I hopped on CL and grabbed what I thought was the best deal I could find in a pinch.
I really felt bad about all your struggles, but shame on you for being deceitful about selling a unit that can potentially put smoke and CO into the living space where my wife stays home with my 3 year old and 6 month old while I'm gone to work. I hope that $800 was worth it.
I understand it's really no different than the manufacturer selling them to the public, but from one man to another I'd expect more ethics and morals.
And mrpelletburner if you aren't the person I bought the FC1000 from, then there is someone imitating you.