Came out today for a chemical smell coming from a Lennox ac system. Model #sl280uh110v6oc-04, serial #5916f02997. Upon inspection there is a strong chemical smell coming from the return side of the blower housing. The evaporator coil’s are clean, the drain pan is clear, and the marv 16 filter was just installed in March. I verified that the blower motor is operating properly and the amp draw is a 4.2. I also verified that the transformer is not burned out. I cannot find any reason for the smell. It is possible that something fell down the return duct. I will talk to PA in the morning about the issue and will have someone from the Chud office reach out to the homeowner tomorrow.