Emergency
Double flash Blue light on Worcester Bosch Greenstar 24i / 28i Junior

Your boiler has automatically turned itself off because the exhaust area is getting too hot, indicating a potential blockage or a problem with how the gases are clearing.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Act immediately

Turn off your boiler and stop using gas appliances. Call a Gas Safe engineer now. This fault can be dangerous if ignored.

What the manual says

Manufacturer manual

Flue overheat sensor has exceeded 105°C

From this model's manual
Verified against the Installation And Servicing Instructions For Greenstar Ri Manufactured Aug 08 Jan 11 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.

Engineer required

This is a emergency severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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All 38 fault codes on the Greenstar 24i / 28i Junior

Seeing a different code? Every code this model can display, in one place.

2 pulses2 pulses / No light2 pulses No light5 pulses5 pulses / No light5 pulses No light6a1213141516171819109115A8Blue indicator light flashingBlue indicator light offBlue light onEAERRORFAFast flashFast flash (Reset button Off)Fast flash / FlashingFast flash / Not a fault codeFast flash / OffLOCKOUTNo lightNo light / Not a fault codeOff (No light)Off / OffOn / OffSlow flashSteady on (Burner lit)

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