Performed furnace clean and tune; inspected the exhaust and intake PVC ensuring all connections were secured, removed and cleaned the burners along with the flame sensor, cycled the system on and checked gas pressures and did make adjustments on both stages, also performed a combustion test verifying no CO in the airstream. I did inspect the humidifier and found that the water shut off solenoid valve has failed office to quote repair. I also took a peek at the AC evaporator coil and did find some indicators of a possible leak I recommend a clean in tune this spring so we can ensure operations this summer. This system is currently operating normal at this time. Job complete