BoilerFaultCodesIdeal ERROR CODE 1 Fault Code
Also written as ERRORCODE1 — same fault.
The Ideal ERROR CODE 1 fault code means: your boiler has failed to ignite or lost its flame and has shut down as a safety precaution.. It appears on 2 Ideal models in our database.
Technical description: LOCKOUT
What causes the Ideal ERROR CODE 1 fault?
This fault occurs when the boiler tries to light but fails to detect a stable flame after several attempts. The most common reasons are a lack of gas supply to the appliance, a worn-out ignition spark, or a faulty sensor that cannot 'see' the flame even if it has lit.
This fault is more common during extreme cold snaps, as freezing temperatures can cause the external condensate pipe to block, preventing the boiler from completing its ignition cycle.
DIY fix possible
Check that your gas pre-payment meter (if applicable) has credit.Ensure the gas isolation valve under the boiler is in the 'on' position.Press the 'Reset' button on the front of the boiler display for 2 seconds.
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Gas Safe Register →Ideal models that show the ERROR CODE 1 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ideal ERROR CODE 1 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