Low
fI- on Worcester Bosch Greenstar R29 40 HE

Your boiler is performing a routine self-check and safety fill of its condensation system because the power was recently switched off and on.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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.

What the manual says

Manufacturer manual

The boiler runs for 15 minutes at minimum heating output to fill the condensate trap, the display (K) alternates between 'fI-' and the flow temperature. This occurs every time the mains supply has been interrupted.

From this model's manual
Verified against the Worcester Bosch Greenstar 25he installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

DIY fix possible

Wait approximately 15 minutes for the 'fI-' sequence to complete automatically.Do not turn off the power or reset the boiler during this time.Ensure the central heating continues to run until the display returns to normal operation.

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