f[ xx Low

Remeha f[ xx Fault Code

Also written as FXX — same fault.

The Remeha f[ xx fault code means: your boiler is simply performing a routine system check or displaying its internal software version, which is a normal operation and not a fault.. It appears on 2 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: Venting cycle/Software version number (Not a fault)

DIY fix possible

Wait a few minutes for the cycle to finishMonitor the display to see if it returns to showing the current water temperatureNo action is required as this is not a fault

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Remeha models that show the f[ xx fault code

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

Source

Remeha f[ xx 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