Takagi · Error codes
Takagi error codes and alerts
Identical code numbers can mean different things on different controllers, so every entry is tied to the documented series, controller and manual version. A code is never a diagnosis.
If you smell gas
- Stop what you are doing. Do not use phones, switches, matches or anything that can spark inside.
- Go outside and leave the door open behind you.
- Call the FortisBC 24-hour emergency line at 1-800-663-9911 or dial 911.
Only after that, call ROMA about the boiler. Official guidance: FortisBC gas leaks and odour.
Takagi T-H3 family tankless water heaters (3-digit error codes, manual 68A255-1)
031
Incorrect DIP switch setting. The DIP switch settings on the PCB are incorrect; check the DIP switches on the computer board (Part #701). Th…
Details
101
Warning for the 991 error code. A warning for the 991 error code; ensure the gas type matches, check the heater altitude DIP switches, intak…
Details
111
Ignition failure. The unit failed to ignite; check the Hi-limit switch, wiring and flame rod, look for a buzzing spark ignition sound, liste…
Lockout
121
Loss of flame. The flame was lost; check the Hi-limit switch, wiring and flame rod, and check the heat exchanger for leaks. The table classi…
Lockout
291
Blocked condensate drain system. The condensate drain system is blocked; remove any blockage in the condensate drain line, neutralizer, and …
Details
311
Outlet thermistor failure (140H/240H/340H) or heat exchanger thermistor failure (540H). The outlet or heat exchanger thermistor failed; chec…
Details
321
Inlet thermistor failure. The inlet thermistor failed; check for connection or breakage of wires and debris on the thermistor. The table cla…
Details
331
Outlet thermistor failure (540H only). The outlet thermistor failed; check for connection or breakage of wires and debris on the thermistor.…
Details
341
Exhaust thermistor failure (Indoor models only). The exhaust thermistor failed; check for connection or breakage of wires and debris on the …
Details
391
Air-fuel ratio rod failure. The air-fuel ratio (AFR) rod failed; check for connection or breakage of wires and soot on the AFR rod. The tabl…
Details
441
Flow sensor failure (Easy-Link System only). The flow sensor failed; check for connection or breakage of wires and debris on the flow sensor…
Details
510
Abnormal main gas solenoid valve. An abnormal main gas solenoid valve; check for connection or breakage of wires and burn marks on the compu…
Details
551
Abnormal gas solenoid valve. An abnormal gas solenoid valve; check for connection or breakage of wires and burn marks on the computer board.…
Details
611
Fan motor fault. The fan motor faulted; check for connection or breakage of wires, dust buildup in the fan motor and burn marks on the compu…
Details
651
Flow adjustment valve fault (Easy-Link System only). The flow adjustment valve faulted; inspect the valve for connection or breakage of wire…
Details
661
Bypass valve fault (540H only). The bypass valve faulted; inspect the bypass valve for connection or breakage of wires, locked motor drive d…
Details
701
Computer board fault. The computer board faulted; check for connection or breakage of wires. The table classifies it as Error.…
Details
711
Gas solenoid valve drive circuit failure. The gas solenoid valve drive circuit failed; refer to the 111 and 121 error codes. The table class…
Details
721
False flame detection. False flame was detected; for indoor models check the condensate drain on the vent collar, and check the heat exchang…
Lockout
741
Miscommunication between water heater and remote controller. Miscommunication between the water heater and remote controller; check the mode…
Details
751
Miscommunication between water heater and built-in controller (Indoor models only). Miscommunication between the water heater and built-in c…
Details
761
Miscommunication in Easy-Link System. Miscommunication in the Easy-Link System; check that the connections between the parent unit and child…
Details
941
Abnormal exhaust temperature (Indoor models only). Abnormal exhaust temperature; check if the set temperature is higher than 140°F and the s…
Details
991
Imperfect combustion. Imperfect combustion; check the gas type, the installation environment, altitude, intake and exhaust blockage, direct-…
Details
Takagi T-D2 tankless water heaters (3-digit error codes, manual 62S051-1)
031
Incorrect DIP switch setting. The DIP switch settings on the PCB are incorrect; check the DIP switches on the computer board (Part #701). Th…
Details
101
Warning for the 991 error code. A warning for the 991 error code; check the gas type, blockage in the intake air or exhaust, direct-vent ter…
Details
111
Ignition failure. The unit failed to ignite; check the Hi-limit switch, wiring and flame rod, look for a buzzing spark ignition sound, liste…
Lockout
121
Loss of flame. The flame was lost; check the Hi-limit switch, wiring and flame rod, and check the heat exchanger for leaks. The table classi…
Lockout
311
Outlet thermistor failure. The outlet thermistor failed; check for connection or breakage of wires and debris on the thermistor. The table c…
Details
321
Inlet thermistor failure. The inlet thermistor failed; check for connection or breakage of wires and debris on the thermistor. The table cla…
Details
331
Mixing thermistor failure. The mixing thermistor failed; check for connection or breakage of wires and debris on the thermistor. The table c…
Details
391
Air-fuel ratio rod failure. The air-fuel ratio (AFR) rod failed; check for connection or breakage of wires and soot on the AFR rod. The tabl…
Details
441
Flow sensor failure (Easy-Link System only). The flow sensor failed; check for connection or breakage of wires and debris on the flow sensor…
Details
510
Abnormal gas solenoid valve. An abnormal gas solenoid valve; check for connection or breakage of wires and burn marks on the computer board.…
Details
611
Fan motor fault. The fan motor faulted; check for connection or breakage of wires, dust buildup in the fan motor and burn marks on the compu…
Details
651
Flow adjustment valve fault (Easy-Link System only). The flow adjustment valve faulted; inspect the valve for connection or breakage of wire…
Details
701
Computer board fault. The computer board faulted; check for connection or breakage of wires and burn marks on the computer board and check t…
Details
721
False flame detection. False flame was detected; for indoor models check the condensate drain on the vent collar, and check the heat exchang…
Lockout
741
Miscommunication between water heater and remote controller. Miscommunication between the water heater and remote controller; check the mode…
Details
761
Miscommunication in Easy-Link System. Miscommunication in the Easy-Link System; check that the connections between the parent unit and child…
Details
991
Imperfect combustion. Imperfect combustion; check the gas type, the installation environment, altitude, intake and exhaust blockage, direct-…
Details
Takagi T-M32 / T-M32 ASME tankless water heaters (3-digit error codes, manual 63T051-5)
031
Incorrect dipswitch setting. The DIP switch setting on the computer board is incorrect. The table classifies it as Error.…
Details
101
Warning for 991 error code. A warning for the 991 error code; check the gas type, blockage in the intake air or exhaust, direct-vent termina…
Details
111
Ignition failure. The unit failed to ignite; check the Hi-limit switch, wiring and flame rod, look for a buzzing spark ignition sound, liste…
Lockout
121
Loss of flame. The flame was lost; check the Hi-limit switch, wiring and flame rod, and check the heat exchanger for leaks. The table classi…
Lockout
311
Output thermistor failure. The output thermistor failed; check for connection or breakage of wires and debris on the thermistor. The table c…
Details
321
Inlet thermistor failure. The inlet thermistor failed; check for connection or breakage of wires and debris on the thermistor. The table cla…
Details
331
Mixing thermistor failure. The mixing thermistor failed; check for connection or breakage of wires and debris on the thermistor. The table c…
Details
391
Air-fuel ratio rod failure. The air-fuel ratio (AFR) rod failed; check for connection or breakage of wires and soot on the AFR rod. The tabl…
Details
441
Flow sensor failure. The flow sensor failed; check for connection or breakage of wires and debris on the flow sensor impeller. The table cla…
Details
510
Abnormal main gas valve. An abnormal main gas valve; check for connection or breakage of wires and burn marks on the computer board. The tab…
Details
551
Abnormal gas solenoid valve. An abnormal gas solenoid valve; check for connection or breakage of wires and burn marks on the computer board.…
Details
611
Fan motor fault. The fan motor faulted; check for connection or breakage of wires, dust buildup in the fan motor and burn marks on the compu…
Details
631
Abnormal external pump. The external pump is abnormal; check whether the pump connected to the central computer board works properly. The ta…
Details
651
Water control valve fault (flow adjustment function). The water control valve (flow adjustment) faulted; inspect the valve for connection or…
Details
661
Water control valve fault (bypass function). The water control valve (bypass function) faulted; inspect the valve for connection or breakage…
Details
701
Computer board fault. The computer board faulted; check for connection or breakage of wires and burn marks on the computer board and check t…
Details
721
False flame detection. False flame was detected; for indoor models check the condensate drain on the vent collar, and check the heat exchang…
Lockout
741
Miscommunication between water heater and remote controller. Miscommunication between the water heater and remote controller; check the mode…
Details
761
Miscommunication in Easy-Link or multi-unit system. Miscommunication in the Easy-Link or multi-unit system; check that the connections betwe…
Details
991
Imperfect combustion. Imperfect combustion; check the gas type, the installation environment, altitude, intake and exhaust blockage, direct-…
Details
Takagi T-M50 / T-M50 ASME tankless water heaters (3-digit error codes, manual 63V051-9)
031
Incorrect DIP switch setting. The DIP switch settings on the PCB are incorrect; check the DIP switches on the computer board (Part #701). Th…
Details
101
Warning for the 991 error code. A warning for the 991 error code; check the gas type, intake and exhaust blockage, direct-vent terminal spac…
Details
111
Ignition failure. The unit failed to ignite; check the Hi-limit switch, wiring and flame rod, look for a buzzing spark ignition sound, liste…
Lockout
121
Loss of flame. The flame was lost; check the Hi-limit switch, wiring and flame rod, check the heat exchanger for leaks, and check the gas su…
Lockout
311
Outlet thermistor failure. The outlet thermistor failed; check for connection or breakage of wires and debris on the thermistor. The table c…
Details
321
Inlet thermistor failure. The inlet thermistor failed; check for connection or breakage of wires and debris on the thermistor, and check the…
Details
331
Mixing thermistor failure. The mixing thermistor failed; check for connection or breakage of wires and debris on the thermistor. The table c…
Details
391
Air-fuel ratio rod failure. The air-fuel ratio (AFR) rod failed; check for connection or breakage of wires and soot on the AFR rod. The tabl…
Details
441
Flow sensor failure (Easy-Link System only). The flow sensor failed; check for connection or breakage of wires and debris on the flow sensor…
Details
510
Abnormal main gas valve. An abnormal main gas valve; check for connection or breakage of wires and burn marks on the computer board, check f…
Details
551
Abnormal gas solenoid valve. An abnormal gas solenoid valve; check for connection or breakage of wires and burn marks on the computer board,…
Details
611
Fan motor fault. The fan motor faulted; check for connection or breakage of wires, dust buildup in the fan motor and burn marks on the compu…
Details
631
Abnormal external pump. The external pump is abnormal; check whether the pump connected to the center computer board works properly. The tab…
Details
651
Flow adjustment valve fault. The flow adjustment valve faulted; inspect the valve for connection or breakage of wires, locked motor drive du…
Details
661
Water control valve fault (bypass function). The water control valve (bypass function) faulted; inspect the valve for connection or breakage…
Details
681
Abnormal external fan motor. The external fan motor is abnormal; check whether the external fan motor connected to the center computer board…
Details
701
Computer board fault. The computer board faulted; check for connection or breakage of wires and burn marks on the computer board and check t…
Details
721
False flame detection. False flame was detected; for indoor models check the condensate drain on the vent collar, and check the heat exchang…
Lockout
741
Miscommunication between water heater and remote controller. Miscommunication between the water heater and remote controller; check the mode…
Details
761
Miscommunication in Easy-Link System. Miscommunication in the Easy-Link System; check that the connections between the parent unit and child…
Details
991
Imperfect combustion. Imperfect combustion; make sure the gas type matches, check the installation environment, intake and exhaust blockage,…
Details
Talk to a boiler technician
Describe what the boiler is doing and get a straight answer about the next step.
On-site service in Greater Vancouver, BC. ROMA lists “Open 7 days” on its site; call to confirm same-day availability.