I had a correction on a connection of two new replacement furnaces at a residence. The max ocpd listed on the nameplate was 25A. (2nd circuit) The existing circuit is #10 cu fed from a 30A breaker. The furnaces came equipped with 2P25A breakers. 110.3 was referenced. The AHJ requested I change out the breakers in the panel to 25's. Well, it happens to be a Fed Pac, and the two breakers combined are over 200 dollars. I just don't see the logic. Does the 25A breaker in the furnace not limit the current? Isn't the 30A breaker merely a feeder supplying power to the furnaces ocpd? Does the circuit need to be double protected? If so, why? The only evidence I can find in the book that it is indeed a violation is not from 110.3, but maybe 240.10. "Where supplementary overcurrent protection is used for luminaires, appliances, and other equipment or for internal circuits and components of equipment, it shall not be used as a substitute for required branch circuit protection." What do you all think?