User Guide
47 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
110 and 310 510
Malfunction
description
Diagnosis
Red
LED
Remote
Remote
7 Seg LED
One
Flash
03* 031*
Incorrect DIP
switch setting
Check the DIP switch settings on the PCB (Part #701).
Five
Flashes
10 101
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.
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.
Three
Flashes
11* 111*
Ignition failure Check if the Hi-limit switch (Part #412) is functioning
properly.
Check for connection/breakage of wires (Part #413, 708, 709,
710, 712), 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).
Three
Flashes
12* 121*
Loss of flame
Check if the Hi-limit switch (Part #412) is functioning
properly.
Check for connection/breakage of wires (Part #413, 708,
709, 710, 712), 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).
Two
Flashes
31* 311*
Outlet
thermistor
failure
Check for connection/breakage of wires and/or debris on
thermistor (Part #407, 408, 411, 716).
Two
Flashes
32* 321*
Inlet thermistor
failure
N/A N/A
331*
Mixing thermis-
tor failure
*These error codes will be cleared when water flow stops.