2012 water furnace Envision nsv042 system is running in very good condition. Homeowners only concern is corrosion on multiple fittings associated with the hot water generator copper lines. Water furnace branded Emerson touch screen thermostat is in good condition with no corrosion or battery lights Visible corrosion buildup on the water lines does indicate a leak at some point in time and possibly a continuous long-term leak. recommend plumbing company replace the damaged fittings and shut off valves. Water flush and power flush the drain system, run test system refrigerant pressures at 126 PSI suction with 14 superheat at 57° Ground loop water pressure is stable at 18psi and in range with a minimum 15 requirement. Air filters are on schedule with homeowner and appear to be in like new condition Humidifier operation is questionable and bypass air flow damper was closed today. Controls were not adjusted All equipment is clean safe and ready for the remainder of Summer