semiatic

Humidifier fault or error on a CPAP machine

When the humidifier’s heater stops working, every one of these machines keeps giving air but without heated humidity. Each maker shows it differently: an icon, a pop-up, a numbered code or an audible alert.

Therapy settings: This page explains what a CPAP machine’s screen or light is telling you, in the maker’s words. It is not medical advice: ask your equipment provider or clinician about your therapy settings, and do not change your pressure or any prescribed setting because of anything here.

ResMed

  1. ResMed AirSense 11 An icon on the screen

    Humidifier fault

    A status-bar icon: the machine has detected a fault in the humidifier. Therapy will run without heating.

    The icon table gives no step. If a problem cannot be fixed with the troubleshooting table, ResMed says to contact your care provider or ResMed, and not to open the device.

    Source: AirSense 11 user guide (Americas) (ResMed, 398133/2, 2021-10), checked 2026-09-29.

  2. ResMed AirSense 10 A morning summary screen

    Humidifier (Sleep Report): might be faulty

    The Sleep Report after therapy shows whether the humidifier is working. The second of its two icons means the humidifier might be faulty.

    What ResMed says to do

    1. Contact your care provider.

    Source: AirSense 10 user guide (AirSense 10 AutoSet, AutoSet for Her, Elite and CPAP, with HumidAir) (ResMed, 378947/1, 2021-02), checked 2026-09-29.

Everything else ResMed’s machines show: ResMed CPAP icons and messages.

Philips Respironics

  1. Philips Respironics DreamStation 2 Words on the screen

    Humidifier Error

    Humidification control is disabled. There may be a problem with the humidifier; therapy will run without humidification.

    What Philips Respironics says to do

    1. Turn off the device and disconnect it from power.
    2. Check by eye that the electrical contacts are clear, then reconnect the power cord.
    3. If the alert continues, contact your provider.

    Source: DreamStation 2 Auto CPAP / CPAP user manual (Philips Respironics, 1143534 R02, 06/11/2021), checked 2026-09-29.

  2. Philips Respironics DreamStation 2 Words on the screen

    Humidifier Off

    The attached battery does not support humidification, so the humidifier is off while you run from the battery pack.

    What Philips Respironics says to do

    1. Disconnect the battery pack and use a compatible power supply, or use the device without humidification.

    Source: DreamStation 2 Auto CPAP / CPAP user manual (Philips Respironics, 1143534 R02, 06/11/2021), checked 2026-09-29.

Everything else Philips Respironics’s machines show: Philips Respironics CPAP icons and messages.

Fisher & Paykel Healthcare

  1. Fisher & Paykel Healthcare SleepStyle Words on the screen

    Error code 400–499

    Humidity may have been disabled. F&P says the device is still safe to use and you will still be treated at your prescribed pressure.

    What Fisher & Paykel Healthcare says to do

    1. Turn the power off and on at the power supply to restart the device.
    2. If the error persists or comes back, consult your healthcare provider. Do not try to repair the device yourself.

    Source: F&P SleepStyle Use and Care Guide (SleepStyle Auto, SleepStyle CPAP) (Fisher & Paykel Healthcare, Use and Care Guide, English section A), checked 2026-09-29.

Everything else Fisher & Paykel Healthcare’s machines show: Fisher & Paykel Healthcare CPAP icons and messages.

React Health

  1. React Health Luna G3 Words on the screen

    Humidifier Failure!!

    When the humidifier is fitted, an audible alert sounds when it fails to work, and the screen shows “Humidifier Failure!!”.

    The alert table gives no step. The manual’s general line: if none of the troubleshooting actions solves a problem, contact your home care provider.

    Source: Luna G3 APAP / Luna G3 CPAP User Manual (React Health, V1.7, issue date February 29, 2024), checked 2026-09-29.

Everything else React Health’s machines show: React Health CPAP icons and messages.

Other things a CPAP machine shows

Sources

Each maker’s own user guide only, read on the date shown. Nothing here comes from third-party CPAP forums or “error code” sites.

Find any icon, message or light on your machine →