User Guide
44 Page
-Fault Analysis of Error Codes-
If the error code is displayed on the computer board of the water heater or remote controller, please
check the following. After checking, consult with the manufacturer.
Troubleshoong
Owner's Guide
110 (T-KJr2) and
310 (T-K4)
510
(T-D2)
Malfunction
description
Diagnosis
Red
LED
Remote
Remote
7 Seg LED
One Time
03 031
Incorrect
DIPswitch setting
• Check the DIPswitch settings on the PCB (Part #701).
Five
Times
10 101
Warning for the
“991” error code
• Check the gas type of the water heater.
• Check if there is any blockage in the intake air and/or
exhaust.
• If the water heater is installed as a direct-vent system,
check whether there is enough distance between the
intake air terminal and the exhaust terminal.
• Check the altitude/elevation of area of where the water
heater is installed.
• Check if there is grease and/or dirt in the burner (Part #101)
and the fan motor (Part #103), especially if the water heater
has been installed in a contaminated area.
Three
Times
11 111
Ignition failure • Check if the Hi-limit switch (Part #412) is properly
functioning.
• Check for connection/breakage of wires (Part #413, 708, 709,
710, 712), burn marks on the computer board (Part #701),
and/or soot on the flame rod (Part #108).
• Check if there is a buzzing spark ignition sound coming
from the burner (Part #101) when water heater prepares
for combustion.
• Listen for the double “clunk” sound coming from gas
valve assembly (Part #102) when water heater goes into
combustion.
• Check if there is leaking from heat exchanger (Part #401).
Three
Times
12 121
Loss of flame
• Check if the Hi-limit switch (Part #412) is properly
functioning.
• Check for connection/breakage of wires (Part #413, 708,
709, 710, 712), burn marks on the computer board (Part
#701), and/or soot on the flame rod (Part #108).
• Check if there is leaking from heat exchanger (Part #401).
Two
Times
31 311
Outlet
thermistor
failure
• Check for connection/breakage of wires and/or debris on
thermistor (Part #407, 408, 411, 716).
Two
Times
32 321
Inlet thermistor
failure
N/A N/A
331
Mixing thermis-
tor failure