ATI-C Installation Manual
42 Page
-Fault Analysis of Error Codes-
If the error code is displayed on the computer board of the water heater or remote controller, please
check the following. After checking, consult with the manufacturer.
Troubleshoong
Owner's Guide
Remote
Green
LED
Malfunction
description
Diagnosis
031
One Time
Incorrect DIP switch
setting
• Check the DIP switch settings on the PCB (Part #701).
101
Five Times
Warning for the “991”
error code
• Check the gas type of the water heater.
• Check if there is any blockage in the intake air and/or
exhaust.
• Check if there is enough distance between the concentric
terminals.
• Check the altitude/elevation of area of where the water
heater is installed.
• 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.
111*
Three Times
Ignition failure • Check if the Hi-limit switch (Part #412) is properly
functioning.
• Check for connection/breakage of wires (Part #413, 708,
709), burn marks on the computer board (Part #701), and/or
soot on the flame rod (Part #108).
• Check if there is a buzzing spark ignition sound coming
from the burner (Part #101) when water heater prepares
for combustion.
• Listen for the double “clunk” sound coming from gas
valve assembly (Part #102) when water heater goes into
combustion.
• Check if there is leaking from heat exchanger (Part #401).
121*
Three Times
Loss of flame • Check if the Hi-limit switch (Part #412) is properly
functioning.
• Check for connection/breakage of wires (Part #413, 708,
709), burn marks on the computer board (Part #701),
and/or soot on the flame rod (Part #108).
• Check if there is leaking from heat exchanger (Part #401).
311*
Two Times
110C & 310C:
Outlet thermistor
failure
510C:
Heat exchanger
thermistor failure
• Check for connection/breakage of wires and/or debris on
thermistor (Part #407, 408, 411, 713).
321*
Two Times
Inlet thermistor failure
331*
Two Times
Outlet thermistor
failure
(510C model only)
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
(Only Easy-Link &
Multi-Unit System)
• 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).