I am really grateful to have these last answers as I would not have known any of that - this is a great forum to ask questions of experts who are not trying to sell you something personally and I really appreciate that you've all taken the time to comment. It's a big expenditure and we work so hard for our money it's a big relief to get this type of advice. I think it's more the blower noise then the burner noise I was worried about as it's right next to our family room but the sound from the vents is important too. I keep hearing they run continuously so that's why I was concerned too. Any other thoughts on these 2 models are appreciated.