Arrived on site, for heating maintenance on Trane 2020 condenser and 2016 Lennox furnace. 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. Complementary air report show high levels of particulate matter. Discussed benefits of air scrubber air purification with homeowner. Homeowner asked for an estimate to his email to look over. Also noticed there was no surge protection on either unit. Recommended surge protection to protect electrical components.