First I live way out in middle of nowhere I have a 5300sqft home that's hell to heat. I been looking around and seen a lot of heaters for this house I have a boiler in my basement that's gas it costs about 800$ a mth to run. so i did my inspections and found everyone complaining about what they bought from different company's....I have never had a wood boiler and have no clue about them. so what i tell you here is from my experience with Heiss heater boiler.. Day one, Met with owner at my house, communication was easy showed up on time and very polite and accommodating to my needs with my financial ability. Quick and to the point about all my issues and concerns and rebuttals to complaints online with proof to its fixes on their stoves. He told me the minimum size to heat my house and what he would have put in to be the best for it. I still went with the minimum size boiler to heat as I am not rich. I was sold on the Model 3000 for my home and told a delivery date and install date. The Stove arrived in excellent clean non cracked, they set it in place and told me what needed done by date to install. I am one day from install on this boiler. YES they require antifreeze and well why wouldn't you water freezes. You Have to use theirs and only theirs for some reason. I am concerned about the Hard water issue I have seen in other posts about pump problems and will see what they say to do about it... the door Is adequate for the fire box I believe. the fire box is massive I mean huge.... I fit inside crouched... well I haven't any complaints thus far and they have been very on point with my calls and reply's in texts or Calling.. stay tuned.