Flame Rod - A.O. Smith T-M50 ASME Service Manual

10-5. Flame rod

Unit Part #
Function
Failure event
Effects on the water
heater if flame rod fails
Error codes when the
flame rod fails
Diagnostic
Color/Number of wires
The flame rod is assembled with the AFR rod.
Leads to computer board
F l a m e r o d
#103
To detect flames while the water heater is in operation.
1. Unable to detect flames when flames actually do occur
2. Detecting a false flame when no flames actually occur
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.
111
1. Visual inspection: connection / breakage of wires or soot buildup on rod.
2. Check amperes: proper range of values shown below.
Orange(17) - Flame rod
(Between the flame rod and
the computer board)
Detecting elements of the flame rod
3 / 4 " ( 1 7 .5 m m )
A F R R o d
T-M50 / T-M50 ASME Service manual
AOS Part # EKK0E
121
19
CONFIDENTIAL
Checkpoint
721
(During operation)
More than DC 1 μA
Ver. 1.05
I