High
03 on Vokera Synergy E

Your boiler has detected a blockage or debris in its exhaust system which is preventing waste gases from being safely removed.

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

Debris in flue system; Debris in flue venturi. Appears if the boiler or flue system has developed a fault.

From this model's manual
Verified against the Vokera Synergy E installation & service manual, page 53.
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 safety sensors detect that the airflow through the exhaust pipe is restricted or blocked. The most common cause is a build-up of dirt within a small component called the venturi, or a mechanical failure in the fan that prevents harmful waste gases from being pushed out of the property.

This fault can be more frequent during autumn and winter, as high winds can blow external debris into the flue or cause pressure shifts that trigger the safety sensor.

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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