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-Fault Analysis of Error Codes-
If the error code is displayed on the computer board of the water heater or remote controller and/or
temperature 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 DIPswitch
setting
• ChecktheDIPswitchsettingsonthePCB(Part#701).
101
Five Times Warning for the
“991”errorcode
• Check the gas type of the water heater.
• 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 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.
• Checkforconnection/breakageofwires(Part#413,708,
709,710,712),burnmarksonthecomputerboard(Part
#701),and/orsootontheflamerod(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
valveassembly(Part#102)whenwaterheatergoes
into combustion.
• Checkifthereisleakingfromheatexchanger(Part#401).
121
Three Times Loss of flame • Check if the Hi-limit switch (Part #412) is properly
functioning.
• Checkforconnection/breakageofwires(Part#413,
708, 709, 710, 712), burn marks on the computer
board (Part #701), and/or soot on the flame rod
(Part#108).
• Checkifthereisleakingfromheatexchanger(Part#401).
311
Two Times Outlet thermistor
failure (240 (T-H3J) /340
(T-H3S) models only)
Heat exchanger
thermistor failure
(540(T-H3)
model only)
• Check for connection/breakage of wires and/or
debrisonthermistor(Part#407,408,411,715).
321
Two Times Inlet thermistor
failure
331
Two Times Outlet thermistor
failure(540(T-H3)
model only)
341
Two Times Exhaust thermistor
failure (Indoor
models only)