Computer Board - A.O. Smith 710 ASME Service Manual

10-14. Computer board

Unit Part #
Function
Failure event
Effects on the water
heater if the computer
board fails
Error codes when the
computer board fails
Diagnostic
Color / Number of wires
#701 AOS Part #
Controls the functions of the most parts in the water heater.
Malfunctioning computer
When the computer board failed, the control from the computer and/or
the multi-system control will be abnormal.
The following are the typical examples of when the computers fail:
1. Unable to control proper combustion during operation.
2. Unable to detect correct signals from any/all water heater sensors.
3. Unable to control water valves, which may cause output temperature
fluctuations.
4. Errors in its self-diagnostics. In order to self-diagnose properly, the
computer sends a low voltage signal into its circuit. When the computer
does not detect a return signal, from this circuit, the "701" error code will
appear.
5. Unable to communicate to other computers in the water heater models
and/or the multi-unit controller (Part # 9007675005) during the multi-unit
system operation.
701
Visual inspection: connection / breakage of wires and or burn marks on the
computer board.
710 / 710 ASME Service Manual
319143-279
721
N/A
5 " ( 1 2 9 m m )
29
CONFIDENTIAL
Ver. 1.00
Checkpoint
741 761
1 - 5 / 8 " ( 4 0 m m )
N/A