Ferroli LED 3 OFF (DHW Mode) Fault Code
Also written as LED3OFFDHWMODE — same fault.
The Ferroli LED 3 OFF (DHW Mode) fault code means: your boiler has lost the ability to measure the temperature of the water used for your taps and shower, so it cannot produce hot water.. It appears on 1 Ferroli model in our database.
Technical description: D.H.W. Sensor fault
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Ferroli models that show the LED 3 OFF (DHW Mode) fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ferroli LED 3 OFF (DHW Mode) fault code information on this page is sourced and cross-checked against the official Ferroli service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026