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Two red lights flash rapidly on Worcester Bosch Greenstar 25Si

Your boiler is currently set to a special testing mode used by engineers to check its performance, rather than operating in its normal heating mode.

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

Appliance is in MAX or MIN mode (Service Mode).

From this model's manual
Verified against the Worcester Boiler 28si 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

Locate the service mode switch or button on the boiler control panel.Ensure it is set back to the 'Auto' or 'Normal' operating position.Turn the boiler off at the fused spur for 30 seconds and then back on to reset the system.

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