ResMed CPAP High Leak: How to Fix Mask and Air Leaks

Quick Answer

ResMed AirSense 10 and 11 devices trigger the High Leak warning when unintentional mask leak exceeds roughly 24 liters per minute for a sustained period during therapy. This is almost always a mask fit issue rather than a device problem. The most common causes are a worn mask cushion that has lost its seal, incorrect headgear strap tension, sleeping position shifting the mask, and mouth breathing with a nasal mask.

When I show up to a call where someone's ResMed is flagging High Leak all night, nine times out of ten the cushion's older than three months and feels like a wet bar of soap. Your therapy's basically broken at that point. The machine's blowing harder trying to compensate but your airway's not getting the pressure it needs. Ignore this long enough and your AHI climbs, you wake up exhausted, and you start thinking the CPAP isn't working. It is. Your mask isn't.

ResmedCpapSeverity: moderate90% DIY Success

Time to Fix

5–20 min

Difficulty

beginner

Parts Cost

$12 – $55

Tools Needed

Mild dish soap (Dawn or similar), Warm water

What Does the HIGH-LEAK Code Mean?

So here's the deal with High Leak. Your ResMed is telling you it can't maintain your prescription pressure because too much air is escaping somewhere it shouldn't. Usually the mask. Occasionally the tubing or that sneaky water tub seal on the AirSense 10. Before you call your DME supplier and demand a new machine, spend ten minutes with the mask fit test first. Most of the time this is a $12 cushion fix, not a $900 equipment problem.

Most Likely Causes

Based on aggregated repair data, here is the probability breakdown for this error code:

Mask cushion worn, hardened, or torn40%

Headgear straps too loose or too tight24%

Wrong mask cushion size for face shape14%

Sleeping position pushing mask off-center12%

Mouth breathing with a nasal or nasal pillow mask10%

Symptoms You May Notice

The 'High Leak' or 'Check Mask Fit' warning shows up on your device screen during or right after a session
You wake up with dry, irritated eyes because air's been blowing up from the nose bridge seal directly into your eyes all night long
There's a steady hissing or whistling you can hear even with your head on the pillow, sometimes loud enough to wake your partner
myAir app shows a leak rate over 24 L/min for a big chunk of your session, sometimes basically the whole night
Mask has slid halfway down your face by morning, or you wake up and find it sitting on the pillow next to you

Can you reset a Resmed cpap to clear the HIGH-LEAK code?

There is no magic button to clear this code because it is a real-time measurement. Once you fix the physical leak, the warning disappears on the next session. If the message is stuck, power cycle the unit by pulling the plug for 30 seconds. On the AirSense 11, ensure the Mask Fit test shows a green smiley face before you go to sleep.

Tools Required for Diagnosis

Mild dish soap (Dawn or similar)Warm waterSoft dry cloth or microfiber towelCPAP mask wipes (optional but faster for daily cleaning)Replacement mask cushion (have one on hand before starting)

Diagnostic Checklist

Follow these steps in order. We start with the easiest external fixes before opening up the machine.

Replacement Parts

If your diagnostic testing proves the component has failed, you will need a replacement. We recommend OEM parts over aftermarket for water-handling components.

Part Name	OEM Number	Estimated Price
ResMed mask cushion (model-specific replacement)N/A · $20–$55	N/A	$20 – $55
ResMed headgear strapsN/A · $20–$45	N/A	$20 – $45
ResMed CPAP chin strapN/A · $12–$25	N/A	$12 – $25
ResMed ClimateLineAir Heated TubingN/A · $35–$55	N/A	$35 – $55

Frequently Asked Questions

What leak rate is normal on a ResMed CPAP?

ResMed draws the line at 24 L/min for unintentional leaks. Every mask has an intentional leak built in, that's the air that's supposed to blow out through the vent holes to flush out CO2 so you're not rebreathing it. That's totally normal and expected. What we're fighting is air escaping from the seal against your skin. If you're consistently seeing 30 or 40 L/min in myAir, you're probably not getting your full prescription pressure and your sleep quality will suffer for it.

Why does my leak only happen at night and not during the mask fit test?

This is one of the most common things I hear, and it makes total sense when you think about it. The mask fit test happens while you're sitting upright and awake, basically the best-case scenario for sealing. At night, a few things change. Your pillow pushes the mask from a different angle when you roll to your side. Your facial muscles relax completely during deep sleep, which can let your jaw drop and break a nasal mask seal. And if you're a hot sleeper, sweat makes your face slippery enough that the cushion loses grip around 2am. A CPAP pillow with side cutouts helps a lot with the pillow problem specifically.

Can high leak damage my CPAP machine?

It won't kill the motor right away, but running at a high leak for months will work the blower way harder than it's designed for. The motor speeds up to chase the pressure target when it detects a leak. If it's constantly running at max RPM trying to compensate, you're shortening the lifespan of the bearings. More importantly, your AHI will probably spike because the machine can't accurately detect or treat breathing pauses during a high leak event. So even if the machine survives, your therapy's compromised the whole time.

How often should I replace my CPAP mask cushion?

ResMed recommends every 30 days, and honestly that's not just a sales tactic. The silicone actually does degrade that fast with nightly use, face oils, and washing. Most of my patients stretch it to 3 months before they notice a real problem, and that's probably fine if you're washing it every single day. But if you're pushing 4 or 5 months, the cushion's definitely contributing to your leak problem even if it doesn't look visibly worn or torn. It's a $12 to $20 fix depending on the mask. Just replace it and see if the warning goes away.

Can I fix a leaking mask without buying any new parts?

Sometimes yeah. If the cushion's relatively new and clean, try repositioning the mask. Take the headgear completely off, lie down in your actual sleep position, then put the mask on and tighten from there. Most people fit their mask sitting upright and then wonder why it leaks when they're lying down. Also try loosening the straps a little. I know that sounds backwards, but over-tightening bows the silicone and actually creates leak paths along the nose bridge. If it's been more than 3 months since you replaced the cushion though, just order the part. You'll spend an hour troubleshooting and still end up buying it anyway.

Related Resmed Cpap Error Codes

Code: HUBResMed CPAP Error Codes: Complete AirSense 10 and 11 Fault Guide Code: PROBLEMSResMed CPAP Common Problems and How to Fix Them Code: LEAK-WATERResMed CPAP Leaking Water: Causes and Fixes Code: PRESSURE-HIGHResMed CPAP Pressure Too High: How to Adjust AirSense Settings

Models Known to Experience HIGH-LEAK Errors

This repair applies to most Resmed cpaps with this error code. Common model numbers include:

AirSense 10 AutoSet, AirSense 10 CPAP, AirSense 10 Elite, AirSense 10 For Her, AirSense 11 AutoSet, AirCurve 10 VAuto, AirCurve 10 ST

Written by

Sarah Kim

Smart Home & Specialty Appliance Tech · 12 years experience

Last verified for technical accuracy on March 15, 2026