We first dealt with Dupont approximately 15 years ago when my in-laws' furnace stopped working while they were away. The entire team were prompt, polite and professional and it was a very positive experience for my wife who had to babysit the house. When it came time to replace our home central air conditioning unit Dupont was our first (and only call). Mario (one of the owners) came out to our house, explained the various options, recommended a Carrier high efficiency unit and gave what I thought was a very reasonable price. After the unit was installed I was concerned that it might be a bit too close to the property line. I called Mario and he came back out to our house the same evening with a colleague and moved the unit. Fast forward to this year and, as the heat arrived, our Carrier stopped working properly. Dupont came out promptly and checked the unit and determined a part had to be replaced. Alas the part had to come from the US but Dupont kept us updated. The part arrived and was immediately installed under warranty. Alas, the next day (a Saturday) the unit did not appear to be working properly so I called back. Mario responded and said he would come out first thing Saturday morning and replace the thermostat which he did. When this did not appear to fix the problem Mario and a colleague came back out on Saturday evening and replaced the motor. Our air conditioner now seems to be working fine. While it was a little frustrating being without AC during a heat wave we recognize that things break down and sometimes the problem is not obvious. We were very impressed with the level of service we received from Dupont, and Mario in particular. In my view Mario went above and beyond. He made us feel like valued customers. We would not hesitate to recommend Dupont to anyone.