ResMed HumidAir Humidifier Troubleshooting — Rainout & Dry Mouth

Hello. If you wake up with a dry mouth, or if water is dripping into your mask from the tubing, your ResMed humidifier needs adjustment. Let's walk through both problems. Problem 1: Dry Mouth or Dry Throat. Dry mouth means your humidity level is too low or the heated tube is not keeping moisture warm enough. Step 1: Increase your humidity level. On AirSense 10 and 11, press the Home button, then select the humidifier icon. The scale runs from 1 to 8. Try increasing by one step per night until dryness resolves. Most users find 4 to 6 works well. Step 2: Enable Climate Control Auto on AirSense 11. If you have an AirSense 11 with the ClimateLineAir heated tube, set Climate Control to Auto. The machine automatically adjusts tube temperature and humidity to prevent both dryness and rainout throughout the night. Step 3: Check your water level. The HumidAir water chamber should be filled to the maximum fill line — not above it. Overfilling causes spitting and sputtering. Underfilling causes dry air earlier in the night. Problem 2: Rainout — Water Condensing in the Tube or Mask. Rainout happens when your bedroom is colder than the air in the tube, causing moisture to condense. Step 4: Reduce tube temperature. If you use a ClimateLineAir heated tube, lower the tube temperature setting by 1 to 2 degrees. This keeps the air slightly drier so it does not condense as quickly. Step 5: Keep the tubing under your blanket. Route the CPAP tube under the covers so the air stays warm from your bedroom to your mask. This is one of the most effective fixes for rainout. Step 6: Use the Climate Control Auto feature. The AirSense 11 and AirSense 10 S (Auto) models with heated tubes can automatically manage this balance. If you do not have a heated tube, consider upgrading — your DME provider can arrange this. Step 7: Empty and clean the water chamber daily. Bacteria and mineral deposits build up quickly in standing water. Use distilled water only — tap water leaves mineral scale that reduces humidifier performance. Still need help? Find a CPAP provider near you →