High
EA on Worcester Bosch Greenstar 30HE

Your boiler is failing to light the gas or isn't detecting that the flame has started, causing the system to shut down for safety.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

What the manual says

Manufacturer manual

Flame not detected.

Shared across the Greenstar Zwbr range
This code is shared by the boilers in this range, which use the same control board. It may not be printed in this exact variant’s manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

What causes this fault?

This fault occurs when the boiler's internal computer tries to start the burner but cannot confirm that a flame is safely lit. The most common reasons are a lack of gas reaching the unit, worn-out sparking components that fail to ignite the fuel, or a dirty sensor that cannot see the flame even if it is present.

This fault is significantly more common during freezing winter temperatures, as the external condensate drainage pipe can freeze and back up, preventing the boiler from lighting.

Engineer required

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

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Related fault codes

All 25 fault codes on the Greenstar 30HE

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

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