BoilerFaultCodesMain E384 Fault Code
The Main E384 fault code means: your boiler thinks a flame is present even when it should be off, causing it to shut down for safety.. It appears on 1 Main model in our database.
Technical description: False flame
What causes the Main E384 fault?
This fault occurs when the boiler's internal sensors detect a flame signal even though the gas valve should be closed and the burner turned off. It is usually caused by a faulty sensing electrode sending a false signal or a control board malfunction that misinterprets electrical interference as a live flame.
This fault can sometimes be more common in damp or cold seasons, as high humidity or moisture ingress into the casing can cause electrical trackage and false readings on the circuit board.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Main models that show the E384 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Main E384 fault code information on this page is sourced and cross-checked against the official Main service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026