I checked the air filter. Customer needs to order a box of 28*30*2 filters. I checked the electrical wiring and electrical systems, including the auxiliary heat strips and all are within specification. I reset blower speeds to factory settings 2,5,7,10 from 2,7,9,10. This will blow warmer air from the unit. I operated the unit on second stage heating mode and recorded 25-30 degree temperature rise across the air coil. I set the flow rate to 3.5psi pressure drop so I could calculate heat of extraction and compare it to printed data. Heat of extraction is 28,000+ btu/hr which is better than printed data. Unit operating normal. Customer and I talked about a few accessories including a humidifier, surge protector and a WiFi thermostat for the geo unit. I sent estimates for all.