Excellent service and workmanship. We were looking at either replacing our steam boiler outright or installing a mini-duct HVAC system in our 1920s home. Cardinal did a whole-house audit and gave us quotes for both jobs. The mini-duct system turned out to be beyond our budget, but Cardinal gave us very reasonable estimate for a replacement boiler. The installation went smoothly and their technician Alex even came out afterward to adjust the swing setting on the thermostat to help even out the heat output. If we had any complaints it was the long lead time to getting them in - but it's a good sign when a contractor is in demand and is to be expected in this area.