A.O. Smith 710 ASME Service Manual page 42

Error Code
Fault of driving circuit for any of the gas
solenoid valves (SV
551
(The computer checks the condition of the
solenoid valves 6 hours after every operation)
1 PCB and /or gas valve fault
V isual inspection of gas valves: connection / breakage of wires.
Normal: DC78 to 100 VDC between COM (blue) & #9 (green)
(during operation)
Normal: DC78 to 100 VDC between COM (blue) & #53 (orange)
(during operation)
Normal: DC78 to 100 VDC between COM (blue) & #73 (red)
(during operation)
V isual inspection of PCB: connection/breakage of wires and/or burn marks
on the computer board.
2 Gas solenoid valve fault (SV
Error Code
Fan motor fault
611
1 PCB and fan motor fault
V isual inspection of fan motor: connection / breakage of wires or dust
buildup (causing electrical shortage)
Normal: 110 to 160 VDC between red & blue (during operation)
Normal: 13 to 17 VDC between yellow & blue (during operation)
Normal: 2.0 to 6.5 VDC between orange & blue (during operation)
Verify fan motor speed of the water heater using the "diagnostics mode" of
the temperature remote controller. See the "12-1. How to diagnose the
water heater using the temperature remote controller."
V isual inspection of PCB: connection / breakage of wires and /or burn marks
on the computer board.
Malfunction description
, SV , and/or SV
1 2
, SV
1
Malfunction description
(Refer to section 10-3 & 10-14)
710 / 710 ASME Service Manual
)
3
Turn off the power supply
Diagnosis
(Refer to section 10-4 & 10-14)
, and/or SV )
2 3
Turn off the power or water supply
Diagnosis
42
CONFIDENTIAL
Ver. 1.00
Cancellation method
Checkpoint
Cancellation method
Checkpoint
C
G