Controls And Settings - A.O. Smith Water Heater 520 Direct Vent Indoor Service Manual

12. Controls and settings

12-1. (A) Diagnosis using the computer board........................................................................................ 55
12-1. (B) Diagnosis using the 9007603005............................................................................................... 56
12-2. Verifying functionality of computer board, Displaying error code history, and Clearing
error code history memory......................................................................................................
12-3. Clearing the "101" and "991" error code.......................................................................................
12-4. AFR rod function................................................................................................................................. 64
12-5. Dipswitch settings.............................................................................................................................. 65
12-6. Assigning unit numbers in the Easy-link system............................................................................
12-7. (A) ON/OFF conditions: Overview................................................................................................
12-7. (B) ON/OFF conditions: BTU requirements.................................................................................
12-8. (A) Pump control ON/OFF conditions (Only for single and Easy-link system)..........................
12-8. (B) Pump control ON/OFF conditions: BTU requirements...........................................................
12-9. Multi-unit system ON/OFF conditions............................................................................................
12-10. Operation time for unit rotation...................................................................................................... 73
12-11. Individual unit operation in easy-link system while parent unit is under abnormal
conditions (Individual operation mode).........................................................................................
12-12. High Altitude Region Support Software (FM+, FM++ and FM+++)............................................
12-13. How to convert unit of set temperature.........................................................................................
12-14. Control for exhaust temperature (520 Indoor only).....................................................................
12-15. Relay selection for the pump control connection.........................................................................
12-16. Alarm port terminal...........................................................................................................................
12-17. Adjusting manifold gas pressure...................................................................................................... 80
12-18. Manually adjusting the fan motor speed........................................................................................ 82
12-19. Freeze protection system.................................................................................................................. 84
12-20. Freeze protection for recirculation systems..................................................................................
12-21. Draining the unit and cleaning the inlet water filter..................................................................... 88
520 Indoor / 520 Outdoor Service Manual
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