So two days ago we had our air stop working. The unit is only 7 years old. My wife called Sierra Air and got the run around, they told her it was out warranty after five years but Todd came out right away, check it out, contacted York and found out we had 10 years, I called Sierra back and still got the run around so even after they admitted it was covered, we decided to pay the extra $400 to go worth Black Mountain. If I don't feel I can trust you I will not give you my business. Labor and other parts would have cost us $1000, so we chose to go with Todd. I still had to pay the $1000 plus $500 for the parts but I can trust Black Mountain.