Takagi AT-KJr3U-IN Installation Manual And Owner's Manual page 51

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.
Green
Remote
LED
031
One Flash
101
Five Flashes
111*
Three Flashes
121* Three Flashes
311*
Two Flashes
321*
Two Flashes
331*
Two Flashes
391
Two Flashes
441 Two Flashes
-Fault Analysis of Error Codes-
Malfunction
description
Incorrect DIP switch • Check the DIP switch settings on the PCB (Part #701).
setting
Warning for the "991" • Check the gas type of the water heater.
error code • 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.
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).
Loss of flame • 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 leaking from the heat exchanger (Part #401).
110U & 310U:
Outlet thermistor
failure
510U:
Heat exchanger
• Check for connection/breakage of wires and/or debris on
thermistor failure
the thermistor (Part #407, 408, 411, 713).
Inlet thermistor failure
Outlet thermistor
failure
(510U model only)
Air-fuel ratio rod failure • Check for connection/breakage of wires (Part #709) and/
or soot on the AFR rod (Part #107).
Flow sensor failure • Check for connection/breakage of wires and/or debris on
(Only Easy-Link & the flow sensor impeller (Part #402).
Multi-Unit System) • Check water filter. Ensure isolation valves are open.
51
Page
Owner's Guide
Troubleshooting
Diagnosis