Atag iC & iS Fault Codes

CombiSystem Natural GasLPG 24-40 kW 2013-present

GC Numbers: 47-311-0147-311-0247-311-0341-311-1341-311-1441-311-1547-311-1547-311-1647-311-1741-311-1941-311-2041-311-21

The fault code is already on your display

Note it down before pressing reset — resetting clears the code immediately. How to read fault codes →

Most common fault codes

Code	Severity	Plain English	DIY
50	Medium	Your boiler has detected a problem with the sensor that manages your hot water temperature, which may result in your taps running cold or having inconsistent heat.	Engineer
117	Emergency	Your boiler has detected that the water pressure inside the system is far too high, causing it to shut down for safety.	Yes
118	High	Your boiler has detected that the water pressure is too low for it to operate safely, or it is struggling to move water through the system.	Yes

Monthly cover means no unexpected bills when your boiler breaks down.

Top rated

OpenFix

Boiler & heating care plans

Hometree

from £12.95/month

HomeServe

from £8.00/month

Affiliate links — we may earn a commission at no extra cost to you.