START HERE—If a problem exists, the service technician should always begin troubleshooting here.STEP ACTION YES NO GO TO1. Remove furnace door first. DO NOT REMOVE BLOWER ACCESS PANEL! Record status of LED’s1-4. See Service Label/Fault Code Instructions (Fig.4). — — 22. Are any LEDs flashing? 5 3 —3. Are any LEDs on solid? (Solid means ON continuously.) 4 8 —4. Go to page number indicated in Index for LEDs 1, 2, 3, or 4 ON SOLID. — — INDEX5. Is RED LED2 flashing? 6 7 —6. Go to page number indicated in Index for RED LED2 FLASHING. — — INDEX7. Go to page number indicated in Index for subsection covering fault code being flashed. — — INDEX8. Is power on? (DO NOT cycle power to unit). 10 9 —9. Turn power on. — — 2010. Remove blower access panel and depress door switch. Use a piece of tape to hold switch closed.Wait a few sec for self test before proceeding to next step. — — 1111. Does problem appear to be low cooling airflow? 12 13 —12. Go to page number indicated in Index for subsection covering NOT ENOUGH COOLING AIRFLOW. — — INDEX13. Make sure thermostat is calling for heat. — — 1414. Make sure thermostat fan control is in AUTO position if equipped. — — 1515. Observe operation of furnace for 20 minutes or until fault occurs. — — 1616. Does a fault occur? 7 17 —17. Is temperature rise below range specified on rating plate when unit is running in high fire? 18 19 —18. Go to page number indicated in Index for subsectioncovering HIGH FIRE TEMPERATURE RISE TOO LOW (COLD BLOW). — — INDEX19. Does furnace operate properly? 31 28 —20. Remove blower access panel and depress door switch. Use a piece of tape to hold switch closed.Wait a few sec for self test before proceeding to next step. — — 2121. Disconnect R thermostat lead, then wait until blower motor stops. — — 2222. Are any LEDs flashing? 24 23 —23. Are any LEDs on solid? (Solid means ON continuously.) 4 25 —24. Is RED LED2 flashing? 6 7 —25. Put setup switch SW-1 in ON position. — — 2626.Record fault codes listed in fault history.NOTE: Read fault codes until they repeat. The last fault code that occurred will flash first fol-lowed by the lowest number fault code. (EXAMPLE: 13, 13, 44)— — 2727. Are LEDs 3 and 4 flashing a Fault Code 11? 29 30 —28. Go to page number indicated in Index for subsection covering NO OPERATION WITH NO FLASH-ING FAULT CODE. — — INDEX29. Go to page number indicated in Index for CLEANUP AND START-UP INSTRUCTIONS. — — INDEX30. Go to page number indicated in Index for subsection covering first fault code flashed. — — INDEX31. Disconnect the R thermostat lead, then wait until blower motor stops. — — 3232. Put setup switch SW-1 in ON position. — — 3333.Record fault codes listed in fault history.NOTE: Read fault codes until they repeat. The last fault code that occurred will flash first fol-lowed by the lowest number fault code. (EXAMPLE: 13, 13, 44)— — 3434. Are LEDs 3 and 4 flashing a Fault Code 11? 35 30 —35.Go to page number indicated in Index for the CLEANUP AND START-UP INSTRUCTIONS. If thisproblem persists on an intermittent basis, replace furnace control board. If problem still persists onan intermittent basis after replacing furnace control board, contact your distributor.— — INDEX6