A.O. Smith 510 Outdoor Service Manual page 42

Error Code
Disconnected AFR rod
391
1 AFR rod fault
V isual inspection: connection/breakage of wires, soot on it.
Error Code
Flow sensor failure (Only Easy-link system)
441
1 Flow sensor failure
V isual inspection: connection/breakage of wires and/or debris on impeller.
Check voltage/resistance between (red & black) or (white & black)
Error Code
Fault of driving circuit for main gas solenoid
valve (MV, SV
510
(The computer checks the condition of the main
gas valve immediately after every operation and
the conditions of the solenoid valves 6 hours
after every operation)
1 PCB and/or main gas valve fault
(Refer to section 10-4 & 10-15)
V isual inspection of gas valves: connection/breakage of wires.
Normal: 78 to 100 VDC between COM (blue) & #3 (light blue)
(during operation)
Normal: 78 to 100 VDC between COM (blue) & #9 (green)
(during operation)
Normal: 78 to 100 VDC between COM (blue) & #53 (orange)
(during operation)
Normal: 78 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 (MV, SV
Malfunction description
Malfunction description
Malfunction description
, SV and/or SV )
1 2 3
510 Indoor / 510 Outdoor Service Manual
Turn off the power or water supply
Diagnosis
(Refer to section 10-6)
Turn off the power or water supply
Diagnosis
(Refer to section 10-9)
Turn off the power supply
Diagnosis
, SV and/or SV )
1 2 3
42
CONFIDENTIAL
Ver. 1.00
Cancellation method
Checkpoint
Cancellation method
Checkpoint
Cancellation method
Checkpoint
I
H2
C