Takagi T-H3J-DV Service Handbook page 12

ERROR CODE GREEN LED ON
COMPUTER BOARD
321 Two Flashes
331 Two Flashes
341 Two Flashes
391
Two Flashes
441
Two Flashes
510
Six Flashes
551
Six Flashes
611 Four Flashes
651 Four Flashes
661 Four Flashes
701 One Flash
711 One Flash
721 Six Flashes
741
751
761
12 • On-Demand Water Heater Service Handbook for 240, 340 & 540 Condensing Models
SYMPTOM OR ISSUE
Inlet thermistor failure
Outlet thermistor failure
(540 model only)
Exhaust thermistor
failure
(indoor models only)
Air-fuel ratio rod failure
Flow Sensor Failure
(Easy-Link or Multi-Link
System)
Abnormal main gas
solenoid valve (MV)
Abnormal gas solenoid
valve (SV1, SV2, and/
or SV3)
Fan motor fault
Flow adjustment valve
fault (Easy-Link or Multi-
Link System)
Bypass valve fault
Computer board fault
Gas solenoid valve drive
circuit failure
False flame detection
Miscommunication
N/A between water heater
and remote controller
Miscommunication
between water heater
N/A and temperature
controller (Indoor
model only)
Miscommunication
between units in an
N/A
Easy-Link or Multi-Link
system. (540/T-H3 Only)
TROUBLESHOOTING PROCEDURE (PAGE NUMBER)
Code 311, 321, 331 or 341: Thermistor Failure, p. 16.
Code 311, 321, 331 or 341: Thermistor Failure, p. 16.
Code 311, 321, 331 or 341: Thermistor Failure, p. 16.
Code 391: Air-Fuel Ratio Rod Failure, p. 17.
Code 441: Flow Sensor Failure (Easy-Link or Multi-Link
System Only), p. 17.
Code 510: Abnormal Main Gas Solenoid Valve (MV), p.
17.
Code 551: Abnormal Solenoid Gas Valve (SV1, SV2, and/
or SV3), p. 18.
Code 611: Abnormal Fan Motor, p. 18.
Code 651: Flow Adjustment Valve Fault (Easy-Link or
Multi-Link System only), p. 18.
Code 661: Bypass valve fault
(540 (T-H3) model only), p. 19.
Code 701: Computer Board Fault / Proportional Gas
Valve Fault, p. 19.
Code 711: High Limit Switch / Overheat Cutoff Fuse
Circuit is Compromised, p. 19.
Code 721: False Flame Detection, p. 20.
Code 741: Remote Control Problem, p. 20.
Code 751: Temperature Controller Problem, p. 20.
Code 761: Communication Error in Easy-Link or Multi-
Link System, p. 20.