ResMed S9 series (S9 AutoSet, S9 Elite, S9 Escape)
Find the message on your screen below. Most alerts clear with a simple check: the water chamber seated, the tube connected, the filter clean. If a code keeps coming back after the fix, stop using the machine and contact your equipment supplier or the manufacturer.
What it means: The machine was left somewhere hot, or there is a fault in your ClimateLine or ClimateLineMAX heated tubing.
What to do: Let it cool, then unplug the power cord and plug it back in to restart. If it comes back, stop using the heated tube, use Standard or SlimLine tubing in the meantime and contact your provider.
What it means: The machine was left somewhere hot, the H5i was refilled with cold water while still hot, it was filled with ice cold or hot water, or the H5i has a fault.
What to do: Let it cool, then unplug and replug the power cord to restart. Use room temperature water and let the humidifier cool before refilling. If the message returns, stop using the H5i and contact your provider.
What it means: The machine overheated, often from a hot room, a blocked air filter, blocked tubing, or water collecting in the tubing from a high humidity setting.
What to do: Let it cool, replace a dirty filter, clear any blockage in the tubing, empty water from the tubing and turn the humidity down, then unplug and replug the power cord to restart.
What it means: The DC plug is not fully in, was inserted too slowly, a non-ResMed power supply is attached, or the power supply is covered by bedding.
What to do: Push the DC plug fully into the back of the machine, use only a ResMed power supply, and uncover the power supply.
What it means: The air tubing is blocked.
What to do: Check the tubing along its length and remove any blockage or kink.
What it means: There is a large leak at the mask, the tubing is loose, or the H5i flip lid is not latched.
What to do: Adjust the mask and headgear, connect the tubing firmly at both ends and close the flip lid until it clicks.
What it means: The H5i flip lid is open or the tubing is not connected properly.
What to do: Close the flip lid until it clicks, connect the tubing firmly at both ends and press any key.
What it means: The SD card is not inserted correctly, or it was removed before new settings were copied to the machine.
What to do: Reinsert the SD card correctly and wait for the Home screen or the Settings updated successfully message. If you expected a settings update and never saw that message, contact your provider right away.
No matching code. Check the exact text on the screen, or see the troubleshooting section on the machine page.
Last reviewed October 11, 2026. How we research · Report an error