54
Page
Troubleshooting
Owner's Guide
Remote
Green
LED
Malfunction
description
Diagnosis
391
Two Times
Air-fuel ratio rod
failure
• Check for connection/breakage of wires (Part #709)
and/or soot on the AFR rod (Part #108).
441
Two Times
Flow sensor failure
(Easy-Link System only)
•
Check for connection/breakage of wires and/or
debris on the flow sensor impeller (Part #402).
510
Six Times
Abnormal main gas
solenoid valve
• Check for connection/breakage of wires (Part #708)
and/or burn marks on the computer board (Part #701).
551
Six Times
Abnormal gas
solenoid valve
• Check for connection/breakage of wires (Part #708)
and/or burn marks on the computer board (Part #701).
611
Four Times 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)
.
651
Four Times Flow adjustment
valve fault (Easy-
Link System only)
•
Inspect the flow adjustment valve (Part #402), for
connection/breakage of wires, locked motor drive
due to scale buildup, and/or water leakage.
661
Four Times Bypass valve fault
(540 (T-H3)
model only)
•
Inspect the bypass valve (Part #403), for connection/
breakage of wires, locked motor drive due to scale
buildup, and/or water leakage.
701
One Time
Computer board fault
• Check for connection/breakage of wires (Part #714).
711
One Time
Gas solenoid valve
drive circuit failure
• Refer to the 111 and 121 error codes.
721
Six Times
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 heat exchanger (Part #401).
741
N/A
Miscommunication
between 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.
751
N/A
Miscommunication
between water heater
and temperature
controller (Indoor
models only)
•
Inspect the connections between the water heater
and temperature controller.
•
Check the power supply of the water heater.
761
N/A
Miscommunication
in Easy-Link System
•
Check if the connections between the parent unit
and the child units are correct. Refer to p. 33 to 36.
941
Five Times
Abnormal exhaust
temperature
(Indoor models
only)
• Check if the set temperature is higher than 140°F
(60°C) and the system is Recirculation.
991
Five Times
Imperfect
combustion
•
Check the gas type of the water heater.
•
Inspect the environment around the water heater.
Determine how long the unit has been installed.
•
Check the altitude/elevation of the area of where
the water heater is installed.
•
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 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.
