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

Your boiler is currently running in a manual testing mode at its maximum power, which is likely a temporary setting used by an engineer during a service.

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 maximum output.

Engineer required

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

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