ATAG iC 24 Boiler Fault Codes

A detected failure is indicated on the display in blocking or error messages.

- Blocking code with spanner symbol: Error is temporary and will cancel itself or will lock the boiler after several attempts (error)

- Error code with bell symbol: Error means a lock on the boiler and can only be remedied by a reset and/or intervention by a service technician.

Code	Fault
10	Outside sensor error (e.g. open, short circuit, out of range)
20	Flow sensor error (e.g. open, short circuit, out of range)
40	Return sensor error (e.g. open, short circuit, out of range)
50	T3 (DHW) sensor error (e.g. open, short circuit, out of range)
61	Bus communication error (contact open)
78	Water pressure outside of range or not connected
105	Venting program active when power turned on or interrupted (runs approx. 7 mins.)
110	Safety temperature exceeded
111	Maximum temperature exceeded
117	Pressure too high (> 3 bar) or pump pressure increase too high
118	Pressure too low (< 1 bar) or pump pressure increase too low (no pump detection)
119	Link on X2 position 4 and 5 missing
129	Fan error (fan does not start up)
133	No flame after 5 ignition attempts
151	Fan error (speed control is not achieved or is out of range) or control unit defective
154	Flow increases to fast ∆T to large, return > flow
180	No error: shortly visible when leaving chimney sweep function
181	No error: shortly visible when leaving commissioning mode