Takagi T-H3J-DV / 240H Installation Manual And Owner's Manual page 51

Green
Remote
LED
311 Two Times
321 Two Times
331
Two Times
341 Two Times
391 Two Times
441
Two Times
510 Six Times
551
Six Times
611 Four Times Fan motor fault
651 Four Times Flow adjustment
661 Four Times Bypass valve fault
701 One Time
711 One Time
721 Six Times
Malfunction
description
Outlet thermistor
failure (T-H3J-DV /
240H and T-H3S-DV
/ 340H only)
Heat exchanger
thermistor failure
• Check for connection/breakage of wires and/or
(T-H3-DV / 540H
debris on thermistor (Part #407, 408, 411, 715).
only)
• Check the resistance.
Inlet thermistor
failure
Outlet thermistor
failure (T-H3-DV /
540H only)
Exhaust thermistor
failure
Air-fuel ratio rod • Check for connection/breakage of wires (Part #709)
failure and/or soot on the AFR rod (Part #108).
Flow sensor failure • Check for connection/breakage of wires and/or
(Easy-Link System only) debris on the flow sensor impeller (Part #402).
• Check the water isolation valves are open.
• Check inlet water filter for debris.
Abnormal main gas • Check for connection/breakage of wires (Part #708)
solenoid valve and/or burn marks on the computer board (Part
#701).
• Check for signs of vent corrosion.
• Check gas valve contacts and gas valve wire harness
connections for signs of rust or corrosion.
Abnormal gas • Check for connection/breakage of wires (Part #708)
solenoid valve and/or burn marks on the computer board (Part
#701).
• Check for signs of vent corrosion.
• 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).
• Inspect the flow adjustment valve (Part #402), for
valve fault (Easy- connection/breakage of wires, locked motor drive
Link System only) due to scale buildup, and/or water leakage.
• Inspect the bypass valve (Part #403), for connection/
(T-H3-DV / 540H breakage of wires, locked motor drive due to scale
only) buildup, and/or water leakage.
Computer board • Check for connection/breakage of wires (Part #714).
fault
Gas solenoid valve • Refer to 111 and 121 error codes.
drive circuit failure
False flame • For indoor models, check if condensate drain is
installed on the vent collar of the water heater.
detection
• Check if there is leaking from heat exchanger (Part
#401).
51
Diagnosis
Page
Owner's Guide
Troubleshooting