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2022 ATAG Boiler Error & Fault Codes


Boiler fault codes are sequenced codes that may appear on the display screen of your boiler. The code that appears will depend on the manufacturer, but each code will have various meanings. If you know what these codes mean, then you can quickly identify and address the problem, regardless of whether you're an engineer or not.

To begin, it is important to understand the role that error codes play in maintaining proper operation. Knowing how different issues correspond to specific code numbers can help you address a problem much faster once it has developed.

Your ATAG boiler can communicate a range of fault codes to your control panel, telling you when a fault has occurred and at times suggesting potential remedies to the problem. It is important that these faults are resolved as soon as possible, as some can lead to further damage should they remain unchecked.

Regular Boiler Error Codes


The ATAG Regular Boiler Error Codes are a series of numerical codes that are displayed by your boiler if you find fault with one of its components. You can use this list to identify the component causing the problem.

Fault Code Possible Cause
10Outside sensor error
20Flow sensor error
40Return sensor error
61Bus communication error
78Water pressure out of range
105Venting program active when power turned on / interrupted (runs for 7 mins)
110Exceeded safety temperature
111Exceeded maximum pressure
119X2 link position 4 and 5 missing
129Fan doesn’t start
133No flame after 5 ignition attempts
151Fan error or control unit defective (speed control is not achieved)
154Return greater than flow – flow temperature increases too fast
101Overheat error
102Pressure sensor fault
104Flow check failed
108Pressure needs filling to < 0.5 bar
1P4Pressure needs filling to 0.5 – 0.8 bar
109Pressure > Pmax error
110Send probe damaged
112Return probe error – could be damanged
114Outdoor sensor error – could be damaged
141Central heating flow switch is open
201Domestic hot water (DHW) probe damaged
203Tank probe damaged
303Printed circuit board (PCB) error
304Too many resets have occured
501No flame detected
612Fan fault – fan isn’t starting up

IC / IS Combi Boiler Error Codes


Each boiler has a number of sensors and control units - if one of these develops a fault, the boiler will display an error code on the LED screen. This is what each code means:

Fault Code Possible Cause
50Domestic hot water (DHW) sensor error
117Pressure greater than 3 bar or pump pressure increase is too high
118Pressure less than 1 bar or pump pressure increase too low (no pump detection).
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