We received a call from the tech abt 20 min before his arrival. He worked on the unit up in the attic, and out behind the house. Very thorough. Showed me pictures of mold in the attic filter and applied cleaning agent. Was very helpful in explaining future things we can do that will help keep things running smoothly and keep us healthy. We have had this unit since 2013, this gentleman was absolutely the most thorough of any of your service people.