T-M50 / T-M50 ASME Service manual
Ver. 1.05
33
CONFIDENTIAL
10-18. Igniter
Unit Part #
#102
AOS Part #
EKN74
Checkpoint
B
Function
-To ignite the gas/air mixtures when the water heater is ready to burn gas on
its burner surface.
-The output voltage of the igniter is more than 14 kVDC.
Failure event
1. Unable to ignite during the ignition process.
2. Makes attempts to ignite at all times.
Effects on the water
heater if the igniter fails
1. The water heater cannot ignite during the ignition process and the "111"
or "121" error codes will display.
2. No effects on the water heater, however, the durability of the igniter
wears down.
Error codes when Igniter
fails
111
121
Diagnostic
1. Visual inspection: connection/breakage of wires and/or an observed weak
spark.
2. Check voltages: proper range of values shown below.
Color/Number of wires
Purple(7)-Purple(7)
90 to 110 VAC
90 to 110VAC
14 kVDC
High-voltage igniter cable
Igniter
Purple wire
1 - 3 / 4 " ( 4 4 m m )
3
/
4
"
(
2
0
m
m
)
1
-
1
/
2
"
(
3
8
m
m
)
P o w e r s u p p l y
A C 9 0 t o 1 1 0 V
T o H i g h v a l t a g e
i g n i t e c a b l e
The high-voltage
igniter cable and
the purple wires
do not come with
EKN74.
