Installation Guide

56 Page
Troubleshoong
Owner's Guide
Controller
Green
LED
Malfunction
description
Diagnosis
331
Two
Flashes
Outlet thermistor fail-
ure (540 model only)
 Check for connection/breakage of wires and/or debris on therm-
istor (Part #407, 408, 411, 715).
341
Two
Flashes
Exhaust thermistor
failure (Indoor models
only)
391
Two
Flashes
Air-fuel ratio rod fail-
ure
 Check for connection/breakage of wires (Part #709) and/or soot
on the AFR rod (Part #108).
441
Two
Flashes
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
Flashes
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
Flashes
Abnormal gas
solenoid valve
 Check for connection/breakage of wires (Part #708) and/or burn
marks on the computer board (Part #701).
611
Four
Flashes
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
Flashes
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
Flashes
Bypass valve fault
(540 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
Flash
Computer board fault  Check for connection/breakage of wires (Part #714).
711
One
Flash
Gas solenoid valve
drive circuit failure
 Refer to the 111 and 121 error codes.
721
Six
Flashes
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 tempera-
ture 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. 37 to 38.
941
Five
Flashes
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
Flashes
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 termi-
nal 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.