I paid over $5700 to Mr. King to install a gas furnace/AC unit. He spent all summer and into the fall doing this work. He has failed to install a filter rack for the furnace to date. I have contacted him and he has not resolved the problem. I am supposed to pay him an additional $100 for this service. I have a new furnace and brand new duct work being compromised daily without benefit of a filter. The furnace warranty is null and void without the completion of this work.