Came out for prepaid heat maintenance on clients less than 1yr old Trane communicating XV20 heat pump system, perform maintenance by putting system in to heat pump test mode and then checking amperages, voltages, temperature rise and temperature split, replaced client provided 20x25x4 filter, washed out outdoor unit with water hose, check surge protectors, and clients Reme halo air purification system etc. etc.. system is operating well within manufacturer spec.