Came out today to perform preventative maintenance on a Lennox system model #cbx32mv-036-230-6-04, serial #5806h14820. Upon inspection I found some sort of microbial growth inside the air handler cabinet. It is passed the point of being cleaned. The system is from 2006 and my recommendation is to replace the system and then get the ducts cleaned. See photos . Preventative maintenance cannot be performed at this time and I strongly recommend not turning the system on. I will reach out to Michelle with all the details.