x[[ Low

Remeha x[[ Fault Code

Also written as X — same fault.

The Remeha x[[ fault code means: your boiler is currently performing a standard task, such as heating your radiators or hot water, and is operating exactly as it should.. It appears on 3 Remeha models in our database.

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

Technical description: Operating mode

DIY fix possible

This fault may be fixable without an engineer. Check your manual first.

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Remeha models that show the x[[ fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Remeha x[[ fault code information on this page is sourced and cross-checked against the official Remeha service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026