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

110 Indoor / 110 Outdoor Service Manual
Ver. 1.01
39
CONFIDENTIAL
Error Code
Diagnosis Checkpoint
11
Error code is
shown after
three failed
attempts at
ignition
6 Disconnected/damaged hi-limit switch. (Refer to section 10-11)
Visual inspection: connection/breakage of wires.
Normal: 1 Ω or less between blue & blue
C1
7 Inspect flame rod
[1] Check for any soot on the rod.
[2] Check the connection of ground wire; make sure there is firm contact to
the ground of the water heater.
(in this case, the wire is contacted to the manifold surface.)
[3] PCB fault
During operation: more than 1 μA through the flame rod wire (orange)
[4] Flame rod fault
During operation: more than 1 μA through the flame rod wire (orange)
I
8 Check if hi
-
limit switch is properly functioning.
Error Code
Malfunction description Cancellation method
12
Error code is
shown after
three failed
attempts at
ignition
Loss of flame
Turn off
the power or w
ater supply
Diagnosis Checkpoint
1 Check gas supply and pressure
(Refer to section 1)
2 PCB fault
[1] No voltage to gas main 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
V
DC
between white & red (during operation)
C
H1
3 Gas solenoid 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
4 Check for soot on the flame rod
[1] Clean the flame rod
[2] PCB fault
During operation: more tha
n
1
μA
thro
ugh the flame rod wire (orange)
I

A.O. Smith T-KJr2-OS Specifications

General

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