We had a slight problem with the first windmill ac after it was working well for a while. We contacted customer support and we went through a series of troubleshooting. We were not able to resolve the issue, so they sent out a replacement unit which is working great! Very friendly people trying very hard to resolve any issues. Awesome air conditioner as well. They are so quiet and cool down the room very well. I would definitely recommend Windmill to a friend!