BoilerFaultCodesTechnical description
Obstruction fumes alarm
What causes this fault?
This fault occurs when the boiler's internal sensors detect that harmful exhaust gases are not able to leave the building freely. The most common reasons are a physical obstruction in the flue pipe, such as a bird's nest or debris, or a mechanical failure in the fan that pushes the air out.
This fault is more frequent during autumn and winter when falling leaves or nesting birds are more likely to block the external vent.
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.
Find a Gas Safe engineer
Search the official register →