High
9x on Vokera Syntesi 25

Your boiler has stopped working because the waste water pipe is backed up or blocked, often due to freezing weather or a buildup of debris.

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

Fault codes 9x appear if the condense trap/pipe has become blocked.

From this model's manual
Verified against the Vokera Linea He 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.

What causes this fault?

This fault occurs when the internal safety sensors detect that the waste water produced by the boiler cannot drain away. The most common reason is a physical blockage in the drainage pipe, which causes water to back up into the boiler's internal trap and triggers an automatic shutdown to prevent internal damage.

This fault is extremely common during periods of freezing weather, as the external portion of the condensate pipe can easily freeze and become completely blocked with ice.

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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