Tim and John did a great job (very professional with a little of Tim's humor at times) on the Carrier Infinity warranty work on my furnace. The coating failure on the secondary HEAT EXCHANGER was a surprise for such a high end engineered product by Carrier, but at least they stood behind the problem in design. Special thanks to Mike Thorton for following up on this project and renewing my faith in Black Diamond. Furnace seems to be working like I expected when I first decided on the Infinity.