Mask Leak / High Leak Rate
Various CPAP Machine
Severity: ModerateWhat Does This Error Mean?
A mask leak warning means air is escaping from your CPAP mask faster than the machine can compensate. The mask may not fit properly, the cushion may be worn, or the headgear is too loose. Reposition the mask and tighten the straps slightly.
Affected Models
- ResMed AirSense 11
- ResMed AirSense 10
- Philips DreamStation 2
- Fisher & Paykel SleepStyle
- Most CPAP/BiPAP machines
Common Causes
- Mask not positioned correctly on the face
- Headgear straps too loose
- Mask cushion worn or dirty
- Wrong mask size
- Facial hair breaking the seal
- Sleeping position shifting the mask
How to Fix It
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Reposition the mask — it should seal without excessive tightness.
Lie down in your sleeping position before adjusting. The mask fits differently lying down vs sitting up.
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Tighten the straps slightly — but not too tight.
Over-tightening can actually INCREASE leaks by distorting the cushion. The mask should seal with gentle pressure.
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Check the mask cushion for wear.
Silicone cushions should be replaced every 1-3 months. A worn cushion loses its ability to conform to your face.
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Clean the mask daily.
Facial oils build up on the cushion and reduce the seal. Wash with mild soap and water every morning.
Frequently Asked Questions
How much leak is acceptable?
Most CPAP machines consider under 24 L/min as acceptable. Some leak is normal — the machine compensates. High leak rates reduce therapy effectiveness.
Does a beard cause mask leaks?
Yes. Facial hair prevents the silicone cushion from sealing against the skin. Full-face masks or nasal pillow masks work better with beards.