This was repairs to existing system. Difficult diagnosis was made by Dan Oesterich, who was determined to solve the problem. He went way way above what anyone could have expected, making multiple trips. He was always polite, always neat and always clearly extremely knowledgeable. We would never ever want to have any diagnostic work done by anyone else. The repairs that he made to our system were masterful. We were both also very impressed at his ability to explain the problem and why this particular solution was warranted. We can not recommend Dan Ostreich highly enough. We hope that he will continue to be the technician for our service area, as we would hate to lose his expertise. He knows everything there is to know about our system!!