Performed maintenance on 5 carrier furnaces 1. Visually inspected condenser coil for debris/ dirty. 2. Inspected condenser fan motor. 3. Inspected condenser fan blades. 4. Inspected/ cleaned wiring connections. 5. Tested for gas leaks 6. Tested functionality and cleaned flame sensor 7. Tested functionality and cleaned pressure switches and ports 8. Inspected / replaced return filter. 9. Inspected return plenum for debris/ dirty. 10. Inspected evaporator coil. 11. Tested functionality and visually inspected surface igniter 12. Checked blower amp draw. 13. Measured temperature differential from supply to return. 20 degrees measured. 14.Drain line tested with gallon of water for clogs and to push anything trying to solidify out Dining room 1 - storage left The blower motor is leaking oil. This is a clear indication that the motor is failing and will likely lock up soon. The high limit switch is turning the unit off before max temperature is reached. This means the switch is faulty an