Just bought a house & the furnace worked fine for several months. We then decided to have it undergo an annual servicing by Holland and there was a performance issue with it after the technician left. The guy who came back out (Neal) did an extremely courteous, stellar job making the situation right "on his dime", as he said. Point is, sometimes issues arise from even new HVAC work. I believe the true test of a company is how they respond in scenarios such as these. Even though our unit was very old, we were not held under any expired warranty rules and charged any additional fees.