I have bought two new HVAC systems from O'Brien Service Company and have been very happy both times. Mike is very knowledgeable and courteous and works with us to find the best fit for our home. The installers and repair technicians have always been on time and very easy to work with. On both occasions we had to replace the system in the middle of summer/winter and they were able to add us to the schedule fairly quickly. I have recommended O'Brien to my friends and neighbors and would definitely work with them in the future.