A.O. Smith T-KJr2-OS User Manual

110 Indoor / 110 Outdoor Service Manual
Ver. 1.01
38
CONFIDENTIAL
Error Code
Diagnosis Checkpoint
10
7 Check if there is dust and lint in burner and heat exchanger, when the water
heater has been installed in laundry room.
8 Check if there is grease and dirt in burner and fan motor, when the water
heater has been installed in restaurant.
9
Check the manifold pressure in the
w
ater
heater.
Error Code
Malfunction description Cancellation method
11
Error code is
shown after
three failed
attempts at
ignition
Ignition failure
Turn off the power or water supply
Diagnosis Checkpoint
1 Check gas supply and inlet
gas
pressure
(Refer to section 1)
2 Check the igniter (Refer to section 10-16)
Visual inspection: connection/breakage of wires and/or observed weak
spark.
[1] Cracks/soot on igniter rod
[2] Improper gap between burner & igniter rod
Normal gap: 0.16" (4mm)
[3] PCB fault
Normal: 90 to 110 VAC at #7 (purple-purple) (during ignition)
[4] Igniter fault
B
3 PCB fault
[1] No voltage to main gas solenoid valve (MV)
Normal: 78 to 100 VDC between COM (blue) & #3 (light blue)
(during operation)
[2] No voltage to gas solenoid valve (SV
2
)
Normal: 78 to 100 VDC between COM (blue) & #53 (orange)
(during operation)
[3] No voltage to gas proportional valve (VG
0
)
Normal: 1 to 15 VDC between white & red (during operation)
C
H1
4 Gas solenoid valve fault
[1] Main gas solenoid valve (MV) fault
Normal: 0.9 to 1.3 kΩ between COM (blue) & #3 (light blue)
[2] Gas solenoid valve (SV
2
) fault
Normal: 1.3 to 1.9 kΩ between COM (blue) & #53 (orange)
[3] Gas proportional valve (VG
0
) fault
Normal:
1
to
15
V
DC
between white & red (during operation)
C
H1
5 Disconnected/damaged O.H.C.F. (Refer to section 10-12)
Visual inspection: connection/breakage of wires.
Normal: 1 Ω or less between blue & blue
C2

A.O. Smith T-KJr2-OS Specifications

General

Brand	A.O. Smith
Model	T-KJr2-OS
Category	Water Heater
Language	English