State 520 - Manual (Page 42)

Troubleshooting
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Page
ERROR CODES
 The units are self diagnostic for safety and convenience when trouble shooting.
 If there is a problem with the installation or the unit, it will display a numerical error code on the 3‐
digit 7‐Seg. LED on the computer board (visible through a window on the front cover) or remote
controller (if installed) to communicate the source of the problem.
 Consult the table on the following page for the cause of each error code.
‐Single unit installations‐
The 7‐Seg LED and remote controller displays the whole 3‐digit error code.
Example: If your unit has the “321” error code (inlet thermistor failure)
 Water heater: It will display “321” on the 7‐Seg LED.
 Remote controller: It will display “321” on its screen.
‐Easy‐Link system for the 520 (T‐H2) models only‐
The 7‐Seg LED of the individual unit with the error in question displays the whole 3‐digit error code.
The
remote controller (if installed) displays a 3‐digit number which signifies which unit has the error,
and what the error code is.
Example: If Unit #2 has the “321” error code (inlet thermistor failure)
 Water heater #2: It will display “321” on the 7‐Seg LED, just like in the Single Unit example.
 Remote controller: It will display “232” on its screen. The first “2” indicates that Unit #2 has the
error. The “32” indicates the first two digits of the “321” error code.
Error code on the
remote controller
Error code on the computer board
3‐digit 7‐Seg. LED
Unit #1
PARENT unit
Unit #2
CHILD unit
Unit #3
CHILD unit
Unit #4
CHILD unit
Remote controller