Why does a bathroom extractor fan whistle only when the window is open?
Our answer
Opening the window changes pressure across the extractor's grille or backdraft damper; clean the grille and have a technician check the flap.
Why this approach makes sense
Materials, cleaning instructions and equipment design vary. Pick a reversible approach that fits the exact surface or appliance.
Before you try it
Check the model instructions and test on a small area before committing to a permanent change.
Questions people ask
What might explain the problem involving a bathroom extractor fan?
Opening the window changes pressure across the extractor's grille or backdraft damper; clean the grille and have a technician check the flap.