Warnings - A.O. Smith DRE PLUS Installation, User And Service Manual

Code and description
031 - 038
(Blocking error)
Power supply error
Problem with power sup-
EN
ply
XXX
(Lock out error)
Control error
Hardware failure
11.1.3
n
Indication
40D
No current detected
No current detected in one
or more heating circuit(s).
70
Cause
Supply voltage not correct.
Voltage to the control board not correct. -
Internal error message from the control-
ler.

Warnings

Note
For the coding of the connections, refer to the Electrical wiring diagram (see A.5).
Cause
Damaged wiring and/or defective heat-
ing element.
Damaged wiring and/or defective cur-
rent sensor.
Measure
The measured voltage must be
400 VAC (-15%, +10%).
Make sure that the wiring of the
400-28VAC transformer (E) is connec-
ted and not damaged.
- Check the transformer fuse (F2).
The measured voltage to the control board
must be 28 VAC (-15%, +10%).
- Cycle power to the water heater to re-
set the error.
- If the error persists, replace the con-
troller.
Remark
Do a performance check. (see 10.3)
- Make sure the wiring of the element
current sensors (D) is correct.
- Replace the wiring and/or the sensor.
Installation, Maintenance and Service part