33
T-KJr2-IN / 110 & T-K4-IN / 310 T-D2-IN / 510
Malfunction description
Diagnosis
Red LED
TK-RE02
TM-RE30
Two Times
31
32
311
321
Output thermistor failure
•
Check for connection/breakage of wires
and/or debris on thermistor (Part #407,
408, 411, 716) .
•
Check the resistance .
Inlet thermistor failure
N/A
N/A
331
Mixing thermistor failure
Two Times
39
391
Air–fuel ratio rod failure
•
Check for connection/breakage of wires
(Part #709) and/or soot on the AFR rod
(Part #108) .
•
Check that the unit connected to a prop-
erly grounded outlet .
N/A
N/A
441
Flow sensor failure (Easy-Link
System only)
•
Check for connection/breakage of wires
and/or debris on the flow sensor impeller
(Part #402, 717) .
•
Check that the water isolation valves
are open .
•
Check inlet water filter for debris .
Six Times
51
510
Abnormal gas solenoid valve
•
Check for connection/breakage of wires
(Part #708) and/or burn marks on the
computer board (Part #701) .
•
Check gas valve contacts and gas valve
wire harness connections for signs of
rust or corrosion .
55
N/A
Abnormal main gas valve
•
Check for connection/breakage of wires
(Part #708) and/or burn marks on the
computer board (Part #701) .
•
Check for signs of vent corrosion .
•
Check gas valve contacts and gas valve
wire harness connections for signs of
rust or corrosion .
Four Times
61
611
Fan motor fault
•
Check for connection/breakage of wires,
dust buildup in the fan motor (Part #103)
and/or burn marks on the computer
board (Part #701) .
•
Check for frozen/corrosion of connectors
(Part #103) .
N/A
N/A
651
Flow adjustment valve fault
•
Inspect the flow adjustment valve (Part
#402), for connection/breakage of wires
(Part #718), locked motor drive due to
scale buildup, and/or water leakage .
One Time
70
701
Computer board fault
•
Check for connection/breakage of wires
(Part #714) and/or burn marks on the
computer board (Part #701) .
•
Check the power supply of the water
heater .
Six Times
72
721
False flame detection
•
For indoor models, check if condensate
drain is installed on the vent collar of the
water heater .
•
Check if there is leaking from the heat
exchanger (Part #401) .
N/A
74
741
Miscommunication between
the water heater and remote
controller
•
Check the model type of the remote
controller .
•
Inspect the connections between the
water heater and remote controller .
•
Check the power supply of the water
heater .
N/A
N/A
761
Miscommunication in Easy-Link
System
•
Check if the connections between the
parent unit and the Child units are
correct . Refer to pg . 18 to 20 .
•
Check that the power is on to all Child
units .
