I replaced the filter in the basement unit and the filter in the return air grill for the attic unit. I operated the units on 100% v.s. heat pump heating and measured very good temperature rise. I forced the defrost cycle on both outdoor units and it cycled normal. I also ran units on aux heat to make sure it was working properly. I checked the electrical wiring and electrical systems, all are within specification. Units are working very well. Customer called the office and asked about billing. Customer was told that the office would send an email to collect payment. I will let Donna know.