Arrived on site for heating maintenance on 2021 train furnace. Homeowner stated all was well with regards to normal unit operation. Proceeded with heating maintenance as scheduled. 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. Noticed suction line sensor error on the thermostat. I cleaned the sensor and reset the system and the error was still present. I reset the system later on and the error went away. Advised homeowner to monitor for this error
