A.O. Smith 120 through 250 Series - Manual (Page 72)

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Instruction manual BFC 72
13.3 Troubleshooting table for displayed errors
Displayed errors
Code + Description Cause Solution Remark
S01 (blocking error)
Open circuit from
temperature sensor T2
at bottom of the tank
Sensor is not (correctly)
connected
Connect the sensor lead to JP3 See the BFC electrical diagram (17 "Appendices")
Damaged cable or
defective sensor
Replace the sensor To replace the necessary parts, you must contact your installation
engineer
S02 (blocking error)
Open circuit in sensor 1
of temperature sensor
T
1
at the top of the
tank
(1)
.
Sensor is not (correctly)
connected
Connect the sensor lead to JP5 See the BFC electrical diagram (17 "Appendices")
Damaged cable or
defective sensor
Replace sensor T
1
To replace the necessary parts, you must contact your installation
engineer
S03 (blocking error)
Open circuit in sensor 2
of temperature sensor
T1 at the top of the tank
(1).
Sensor is not (correctly)
connected
Connect the sensor lead to JP5 See the BFC electrical diagram (17 "Appendices")
Damaged cable or
defective sensor
Replace sensor T
1
To replace the necessary parts, you must contact your installation
engineer
S04 (blocking error)
Open circuit from
dummy 1
Dummy is not
(correctly) connected
Connect the dummy sensor (dummy sensor 1 and 2) leads to JP4. See the BFC electrical diagram (17 "Appendices")
Defective dummy Replace the dummy sensor To replace the necessary parts, you must contact your installation
engineer
S05 (blocking error)
Open circuit from
dummy 2
Dummy is not
(correctly) connected
Connect the dummy sensor (dummy sensor 1 and 2) leads to JP4. See the BFC electrical diagram (17 "Appendices")
Defective dummy Replace the dummy sensor To replace the necessary parts, you must contact your installation
engineer
S11 (blocking error)
Short circuit in the
temp. sensor T2 at the
bottom of the tank
Short circuit in sensor
circuit
Replace sensor T
2
To replace the necessary parts, you must contact your installation
engineer