Arrived to check on humidifier. Humidifier was not functional at this time. We are going to install a new bypass humidifier and new water line. While here I did a check on your furnace. It’s from 2003. Heat exchanger has lots of rust. Carbon monoxide test was 0ppm. System is running safe at this time. We need to have the heat exchanger checked for sure next year. We will be out on Dec. 23rd for humidifier install. Thanks for choosing LBA. Merry Christmas!