Chaffoteaux Lockout Fault Code
Also written as LOCKOUT — same fault.
The Chaffoteaux Lockout fault code means: your boiler has stopped working because it cannot light its internal flame or keep it burning, which has triggered a safety shut-down.. It appears on 3 Chaffoteaux models in our database.
Technical description: Flame extinguishes: When the ionisation probe fails to detect flame presence. If a flame is not detected within 10 seconds, the safety solenoids will close. The red lockout indicator 35 illuminates and the display shows the error code.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Chaffoteaux models that show the Lockout fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Chaffoteaux Lockout fault code information on this page is sourced and cross-checked against the official Chaffoteaux service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026