Low
Red LED two flash sequence on Worcester Bosch Greenstar CDi Compact

Your boiler has been manually set to run at its lowest possible power level, usually because a technician is performing a service or safety check.

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.

Technical description

Service mode: Boiler is operating at minimum output.

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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