510
Indoor / 510 Outdoor Service Manual
Ver. 1.00
21
CONFIDENTIAL
10-5. Flame rod
Unit Part #
#108
AOS Part #
319143-035
Checkpoint
I
Function
To detect flames while the water heater is in operation.
Failure events
1. Unable to detect flames when flames actually do occur.
2. Detecting a false flame when no flames actually occur.
Effects on the water
heater if flame rod fails
1. The water heater stops operating. The "111” and/or “121” error code(s)
will display.
2. The water heater will not initiate the ignition process. The "721” error
code will display.
Error codes when the
flame rod fails
111
121
721
Diagnostic
1. Visual inspection: connection / breakage of wires or soot buildup on rod.
2. Check Amperes: proper range of values shown below.
Color/Number of wires
Orange(17) - Flame rod
(Between flame rod and the
computer board)
(During operation)
More than DC 1
μ
A
The flame rod is assembled with the AFR rod.
A F R R o d
F l a m e r o d
Leads to computer board
Detecting elements of the flame rod
3 / 4 " ( 1 7 .5 m m )
1
/
4
"
(
7
.5
m
m
)
1
/
2
"
(
1
2
m
m
)
1
-
1
/
8
"
(
2
9
.3
m
m
)
1
-
3
/
4
"
(
4
4
m
m
)
