Upon my arrival I performed a 6 month checkup on 1 furnace system. Flushed and treated the water removal system, installed new iFLO cartridge, cleaned the flame safety sensor, verified fuel delivery pressures, checked for CO then verified system safety and performance. I found everything performing to manufacture specifications at this time. While onsite the system control has an error code 13-82 system control upgrade needed. I attempted to hook the comfort control to WiFi to install the update but we could not fins the correct password. I advise that the customer try to figure out the password and connect WiFi to the comfort control so it can perform the needed update.