BoilerFaultCodesIdeal LED4 Fault Code
The Ideal LED4 fault code means: your boiler is receiving electrical power and is currently functioning normally, as this light is a status indicator rather than a fault.. It appears on 1 Ideal model in our database.
Technical description: Mains electricity on
What causes the Ideal LED4 fault?
This LED is not actually a fault, but an indicator that your boiler is connected to the mains electricity and receiving power. It signifies that the internal control board is live and ready to operate the heating or hot water when called upon. If this is the only light visible, it confirms the unit is in a standard standby or operational state.
DIY fix possible
This fault may be fixable without an engineer. Check your manual first.
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Gas Safe Register →Ideal models that show the LED4 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ideal LED4 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