Listed below are the common Atag fault codes as described by the boiler manufacturer along with a possible cause.
ATAG Boiler Error Codes
When your ATAG boiler has an error, you will see an error symbol like the one above. This symbol is normally accompanied by one of the codes in the tables below.
| Fault Code | System Behaviour |
|---|
| 10 |
Outside sensor error |
| 20 |
Flow sensor error |
| 40 |
Return sensor error |
| 61 |
Bus communication error |
| 78 |
Water pressure out of range |
| 105 |
Venting program active when power turned on / interrupted (runs for 7 mins) |
| 110 |
Exceeded safety temperature |
| 111 |
Exceeded maximum pressure |
| 119 |
X2 link position 4 and 5 missing |
| 129 |
Fan doesn’t start |
| 133 |
No flame after 5 ignition attempts |
| 151 |
Fan error or control unit defective (speed control is not achieved) |
| 154 |
Return greater than flow – flow temperature increases too fast |
| 101 |
Overheat error |
| 102 |
Pressure sensor fault |
| 104 |
Flow check failed |
| 108 |
Pressure needs filling to < 0.5 bar |
| 1P4 |
Pressure needs filling to 0.5 – 0.8 bar |
| 109 |
Pressure > Pmax error |
| 110 |
Send probe damaged |
| 112 |
Return probe error – could be damanged |
| 114 |
Outdoor sensor error – could be damaged |
| 141 |
Central heating flow switch is open |
| 201 |
Domestic hot water (DHW) probe damaged |
| 203 |
Tank probe damaged |
| 303 |
Printed circuit board (PCB) error |
| 304 |
Too many resets have occured |
| 501 |
No flame detected |
| 612 |
Fan fault – fan isn’t starting up |
IC & IS Combi Boiler Error Codes
| Fault Code | System Behaviour |
|---|
| 50 |
Domestic hot water (DHW) sensor error |
| 117 |
Pressure greater than 3 bar or pump pressure increase is too high |
| 118 |
Pressure less than 1 bar or pump pressure increase too low (no pump detection). |
Other Fault Codes
If you see a spanner symbol this could be one of two things; firstly it could mean your boiler is in service mode. Secondly it could be blocking, if the boiler is blocking the code is only temporary and will clear itself or will lock the boiler after several attempts if the error keeps on occurring.
ATAG Error code 133
If you are seeing the error code 133, your boilers flame is failing after 5 ignition attempts. This could be down to your condensate drain pipe freezing. A frozen condensate pipe is something that is often easily fixed.
