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Page
-Fault Analysis of Error Codes-
If the error code is displayed on the computer board of the water heater or the controller, please check
the following. After checking,
consult with the manufacturer
.
Troubleshooting
Owner's Guide
Remote
Green
LED
Malfunction
description
Diagnosis
031
One Flash
Incorrect DIP switch
setting
•
Check the DIP switch settings on the PCB (Part #701).
101
Five Flashes
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 exhaust
and air intake 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 Flashes
Ignition failure
•
Check if the Hi-limit switch (Part #412) is properly
functioning.
•
Check for connection/breakage of wires (Part #008, 413, 708,
709), burn marks on the computer board (Part #701), and/or
soot on the flame rod (Part #107) and the ignitor (Part #108).
•
Ensure that the gas supply is turned on. If your water
heater has been properly converted to use propane,
ensure that the tank is not empty.
•
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 the gas
valve assembly (Part #102) when the water heater goes
into combustion.
•
Check if there is leaking from heat exchanger (Part #401).
121*
Three Flashes
Loss of flame
•
Check if the Hi-limit switch (Part #412) is functioning
properly.
•
Check for connection/breakage of wires (Part #008, 413,
708, 709), burn marks on the computer board (Part #701),
and/or soot on the flame rod (Part #107) and the ignitor
(Part #108).
•
Ensure that the gas supply is turned on. If your water
heater has been properly converted to use propane,
ensure that the tank is not empty.
•
Check if there is leaking from the heat exchanger (Part #401).
311*
Two Flashes
110U & 310U:
Outlet thermistor
failure
510U:
Heat exchanger
thermistor failure
•
Check for connection/breakage of wires and/or debris on
the thermistor (Part #407, 408, 411, 713).
321*
Two Flashes
Inlet thermistor failure
331*
Two Flashes
Outlet thermistor
failure
(510U model only)
391
Two Flashes
Air-fuel ratio rod failure
•
Check for connection/breakage of wires (Part #709) and/
or soot on the AFR rod (Part #107).
441
Two Flashes
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).
•
Check water filter. Ensure isolation valves are open.
*These error codes will be cleared when water flow stops.
