Takagi Non-Condensing error codes
Takagi's non-condensing range, and the one place on this site where the same fault is displayed three different ways. A T-D2 shows a three-digit code on its 7-segment LED; a T-K4 or T-KJr2 shows a two-digit code on the remote, and without a remote it flashes a red LED a set number of times. Every page below carries all of them. The table is also shorter than the condensing one: there is no exhaust thermistor, no exhaust fan motor, no external pump, no bypass valve, no hi-limit code and no abnormal exhaust temperature — those faults belong to the condensing models.
Not your models? Check the model-number decoder before you read the table below — the code numbers repeat across series and the meanings do not.
| Code | Error | Verdict |
|---|---|---|
| 031 | Incorrect DIP switch settings | Call a pro |
| 55 | Abnormal solenoid gas valve (T-K4, T-KJr2) | Call a pro |
| 101 | Abnormal combustion (warning) | Call a pro |
| 111 | Ignition failure | Call a pro |
| 121 | Flame loss | Call a pro |
| 311 | Output thermistor fault | Part replacement |
| 321 | Inlet thermistor fault | Part replacement |
| 331 | Mixing thermistor fault (T-D2) | Part replacement |
| 391 | Air-fuel ratio rod failure | Call a pro |
| 441 | Flow sensor fault (Easy-Link systems) | Part replacement |
| 510 | Abnormal gas valves | Call a pro |
| 611 | Fan motor fault | Call a pro |
| 651 | Flow adjustment valve fault (Easy-Link systems) | Part replacement |
| 701 | Computer board fault | Call a pro |
| 721 | False flame detection | Call a pro |
| 741 | Remote controller communication failure | Part replacement |
| 761 | Easy-Link communication failure | Call a pro |
| 991 | Abnormal combustion | Call a pro |
Every entry above is transcribed from the manufacturer's diagnostic documentation for this exact series, with the source cited on each code page.
Other Takagi series
Different series, different code table — if your unit isn't a Non-Condensing, check yours: