47
Page
Remote
Green
LED
Malfunction
description
Diagnosis
391
Two Times
Air-fuel ratio rod
failure
•
Check for connection/breakage of wires (Part #708)
and/or soot on the AFR rod (Part #108)
510
Six Times
Abnormal main gas
solenoid valve
•
Check for connection/breakage of wires (Part #707)
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
551
Six Times
Abnormal gas
solenoid valve
•
Check for connection/breakage of wires (Part #707)
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
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)
701
One Time
Computer board fault
•
Check for connection/breakage of wires (Part #711)
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 temperature
controller
(Indoor
model only)
•
Inspect the connections between the water heater
and temperature controller
•
Check the power supply of the water heater
941
Five Times
Abnormal exhaust
temperature
(Indoor
model only)
•
Check to see of the exhaust temperature is higher
than 149°F (65°C)
991
Five Times
Imperfect
combustion
•
Check if the gas type of the water heater matches
the gas supplied to it
•
Inspect the environment around the water heater
Determine how long the water heater has been
installed and match DIPswitches
•
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
•
Check the DIPswitches match gas type of the water
heater
•
Check the manifold pressure at Max and Min
•
Check combustion chamber tube (part #117) to see if it
is clear and securely installed
Troubleshooting
Owner's Guide