User Guide

69 Page
Troubleshoong
Owner's Guide
Remote
Green
LED
Malfunction
description
Diagnosis
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).
631
Four
Times
Pump fault
 Check for connection/breakage of wires in the pump(Part #726).
 Check if the water in the pump has frozen (Part #726).
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
 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
 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 built-in
controller (Indoor
model only)
 Inspect the connections between the water heater and built-in
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 pp. 40 and 41.
941
Five
Times
Abnormal exhaust
temperature
(Indoor model only)
 Check if the inlet and return water temperature is higher than
140°F (60°C) in the recirculation system.
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.