BoilerFaultCodesIdeal 2C Fault Code
The Ideal 2C fault code means: your boiler has shut down because a safety sensor has detected that the internal heat exchanger is getting too hot.. It appears on 1 Ideal model in our database.
Technical description: Safety sensor of the heat exchanger is overheated.
What causes the Ideal 2C fault?
This fault occurs when water cannot travel through the boiler fast enough to take the heat away, causing the internal temperature to spike. The most common reasons are a failed pump that isn't pushing water round or a blockage caused by a buildup of sludge and debris in the system. Small air pockets trapped within the heat exchanger can also trigger this safety shutdown.
This issue often appears when the heating is first turned on in autumn, as pumps can seize up after being inactive over the summer months.
DIY fix possible
Check that your radiator valves (TRVs) are fully open to allow water to flow.Ensure there are no blockages or blankets covering the boiler casing.Press the reset button once to see if the fault clears after the system has cooled.
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Gas Safe Register →Ideal models that show the 2C fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ideal 2C fault code information on this page is sourced and cross-checked against the official Ideal service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026