B) Diagnosis Using The 9007603005 - A.O. Smith Water Heater 520 Direct Vent Indoor Service Manual

12-1. (B) Diagnosis using the 9007603005

< Individual unit>
1. Press the "HOT" button and the "COLD" button simultaneously for
at least 5 seconds to enter "Diagnostic mode".
2. Scroll up or down to the needed information (mode #) of the 520
Indoor or 520 Outdoor by pressing the "HOT" or "COLD" buttons
(Fig.1 shows mode #5 being selected.)
When selecting information, please refer to the table on p. 58
and p.59 for the proper mode #.
3. Press the "INFO" button to select the mode #, and the
information to which the mode # correlates to will display on the
9007603005 (Fig.2).
4. When the "ON/OFF" button is pressed or 5 minutes have elapsed
without pressing any buttons, the display will return to normal.
Mode #
Fig.1
520 Indoor / 520 Outdoor Service Manual
"INFO"
Button
Information
Fig.2
56
CONFIDENTIAL
Ver. 1.00
"HOT"
"TIME"
Button
Button
"BUZZER" "ON/OFF"
Button
"COLD"
Button
Button