BoilerFaultCodesIdeal 2S02 Fault Code
The Ideal 2S02 fault code means: your boiler is confused by how your heating controls are wired and thinks it should be receiving two different signals to turn on at once.. It appears on 3 Ideal models in our database.
Technical description: 2x Switched Live Mode selected.
What causes the Ideal 2S02 fault?
This fault occurs when the boiler receives an electrical command to turn on from two different external sources at the same time, which confuses the system's logic. The most common reason is that the external thermostat or programmer has been wired into two separate terminals on the circuit board by mistake. It can also happen if a faulty smart home controller is sending conflicting signals to the boiler.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Ideal models that show the 2S02 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ideal 2S02 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