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240 (T-H3J), 340 (T-H3S) and 540 (T-H3) models Service Manial
Ver. 1.00
CONFIDENTIAL
10-5. Flame rod
Part #
• 319143-517 (EK193)
Unit Part#
#108
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 - Flame rod
(Between the flame rod
and the computer board)
(During operation)
More than DC 1 μA
Check
point
I
The flame rod is assembled with the AFR rod.
3/4" (19.5 mm)
1" (27 mm)
1/2" (12 mm)
2-1/8" (54 mm)
Lead to computer board
Detecting elements of the flame rod
Black mark