Where the 1 star review came from I couldn't tell you? I have used Marks AC 3 times all were only a 5 star rating. As far as using used parts that has never been the case when I have used them, all were new and i physically seen the old and new put in and my unit warranty was honored. Maybe the 1 star review expects labor when most warranties don't cover after the first couple of years....and hello ask to see the new and old parts, I did as was shown without hesitation. As far as BBB is concerned that whole rating is a joke considering it was based on complaints that appear to be resolved. I'd rather use a company that has a single complaint and a lower rating than 1 that has hundreds and somehow gets better..what a joke. All i know I needed Marks AC today and again they delivered.... 85.00 got my AC running and courteous,honest and reliable service. Let the reviews speak for themselves, all on here On yelp except 1 and all 90 on yellow book pages are 5 star. Obviously you can't make everyone happy (1 person) but 98 out 99 ain't too bad. Keep up the good work Marks AC, there are those of us who do appreciate good service.... Thanks