A.O. Smith T-M50 ASME Service Manual page 53

C. With multi-unit system installations:
Example: If Unit #2 fails on the "321" error (inlet thermistor). See the pictures below.
Central computer board: The unit that has the error in the multi-unit system will display the error
code on its 7-Seg LED in exactly the same way as if it were only a single Unit. So, in this example, the
7-Seg LED on Unit #2 will display "3".... "2".... "1", just like in the single-unit example above.
When the right and/or left combustion section has an error code, the red lamp next to the 7-Seg
LED on the central computer board will flash to indicate which combustion section has the error
code. Refer to p.49.
Remote controller: The remote controller will display "232" on its screen in its entirety. The first "2"
indicates that Unit #2 has the error. The "32" indicates the first two digits of the "321" error code.
Multi-unit controller (TM-MC01): The Unit # LED on multi-unit controller will flash to inform which
T-M50 has the error code. The multi-unit controller does not display the actual error codes on its 7-seg
LED. The remote controller will display the error codes instead.
Multi unit
T-M50
Controller
#1
Remote
T-M50 T-M50
#2
#3
53
T-M50 / T-M50 ASME Service Manual
Priolity
Multi-system
Mode
set
alarm
Remote control
Set
(RE10)
Error
recall
Pump
test
Alarm
reset
Clear error
Freeze
test
memory
protection
The Unit# LEDs
Computer board of multi-unit
controller (TM-MC01)
CONFIDENTIAL
Ver. 1.05
7 - s e g L E D
Unit No.
Unit1 Unit2 Unit3 Unit4 Unit5
Unit6 Unit7 Unit8 Unit9 Unit10
Unit11 Unit12 Unit13 Unit14 Unit15
Unit16 Unit17 Unit18 Unit19 Unit20
Re-cir
store 2unit
priority
Energy
saving
Select by pulling
out connecter