ResMed Humidifier Fault: What It Means & What to Do
Quick answer
On AirSense 11, ResMed says a Humidifier Fault is detected in the humidifier and therapy runs without heating. On legacy H5i documentation, a humidifier fault is a service issue. Check the tub or side cover only as the matching guide directs and contact your provider if the fault persists.
Equipment: CPAP · Fault type: display message · Severity: high
What Humidifier Fault means
Humidifier Fault identifies a problem in the humidifier system, but the user consequence depends on the device family. The AirSense 11 guide says therapy can run without heating; the H5i guide directs the user to discontinue use and contact the provider.
Meaning varies by model or source
- AirSense 11 — ResMed official user guide: Humidifier fault is detected; therapy will run without heating.
- H5i — ResMed official user guide: A fault in the heated humidifier requires discontinuing use and contacting the clinician or service provider.
Check the tub or side cover
With therapy stopped and the device disconnected, verify only that the user-accessible tub or side cover is correctly seated and not visibly damaged. Follow the exact model guide.
What you can safely check
- Stop therapy and read the complete displayed message before doing anything else.
- Disconnect power using the device power connector or power supply; do not open the enclosure.
- If overheating is implicated, move the device away from heat and allow it to cool before reuse.
- Inspect the external air filter for blockage and replace it only as the user guide directs.
- Inspect the air tubing for blockage, kinks, damage, or water.
- Where relevant, verify that the humidifier tub or side cover is seated correctly and dry.
- Reconnect power and perform ONE restart only when the manufacturer's user guide allows it for that message.
- If the fault returns, therapy is unavailable, or the message is unrecoverable, contact your CPAP equipment provider or authorized service center. Follow your care provider's guidance if therapy cannot be used.
What not to do
- Do not open the enclosure or replace internal electronics, blower hardware, sensors, or boards yourself.
- Do not perform calibration, enter undocumented service menus, bypass safety mechanisms, or change therapy-pressure settings to work around the fault.
Which models are covered?
- AirSense 11
- H5i heated humidifier
- H5i
If the message returns
Contact your CPAP equipment provider or authorized service center. If therapy is unavailable, follow the guidance from your care provider rather than improvising a replacement setting.
Related ResMed CPAP faults
High Leak Detected · Heated Tube Fault · High Temperature Fault
Sources
- ResMed AirSense 11 — official user guide — manufacturer-support; verified 2026-09-03
- ResMed H5i heated humidifier — official user guide — manufacturer-support; verified 2026-09-03
Related CPAP guides
CPAP High Leak: What to Check · CPAP Machine Error: Safe Checks Before Calling Your Provider