Which CPAP Water Chamber Fits Your ResMed Machine? Cleaning and Water Tips
Quick answer: ResMed water chambers are model-specific. The AirSense 10 uses the HumidAir tub, and the AirSense 11 uses the HumidAir 11 tub. They aren’t interchangeable. Each comes in a standard version (hand-wash only) and a cleanable version (dishwasher safe, top rack). Fill your chamber with distilled water, empty it every morning, wash it weekly, and replace it about every six months, or sooner if it’s cloudy, cracked or leaking.
Which water chamber fits your machine?
| Water chamber | Fits | Doesn’t fit | Dishwasher safe? | Capacity |
|---|---|---|---|---|
| HumidAir Standard (AirSense 10) | AirSense 10, AirCurve 10, AirStart 10 | AirSense 11, S9 | ❌ Hand wash only | 380 mL |
| HumidAir Cleanable (AirSense 10) | AirSense 10, AirCurve 10, AirStart 10 | AirSense 11, S9 | ✅ Top rack | 380 mL |
| HumidAir 11 Standard | AirSense 11, AirCurve 11 | AirSense 10, AirCurve 10, S9 | ❌ Hand wash only | 380 mL |
| HumidAir 11 Cleanable | AirSense 11, AirCurve 11 | AirSense 10, AirCurve 10, S9 | ✅ Top rack | 380 mL |
Not sure which you have? Check the name printed on your machine. On AirSense 10 tubs, the marking just above the maximum fill line tells you the version: “HumidAir S” is the standard tub, and “HumidAir C” is the dishwasher-safe tub.
Upgrading from an AirSense 10 to an AirSense 11? Your old tub won’t fit the new machine. See what else changes between the AirSense 10 and 11 →
Standard or cleanable: which should you buy?
Standard tub
- Hand wash only
- Lower price
- Fine if you’re happy to wash by hand each week
Cleanable tub
- Can go in the dishwasher (top rack), and comes apart for easier cleaning
- Typically costs a little more
- Worth it if you’d rather not hand-wash, or if you’ve had trouble keeping a standard tub clean
Both deliver the same humidification. The difference is only how you clean them.
Can you use tap water in a CPAP humidifier?
Use distilled water. Manufacturers and suppliers recommend it because tap water contains minerals that leave a white, chalky film in the chamber. Over time that build-up is hard to clean, can affect the heater plate, and shortens the life of the tub.
A few more water rules:
- Fill with room-temperature water, never hot
- Fill only to the maximum line marked on the chamber
- Don’t add anything to the water. No essential oils, scents, cleaning additives or vinegar left in the tub.
- Refill fresh each night. Don’t top up yesterday’s water.
How to clean your CPAP water chamber
Every morning
- Make sure the hose isn’t holding water, then remove the chamber.
- Empty any water left over.
- Leave it open to air-dry, out of direct sunlight.
Once a week
- Wash the chamber in warm water with a mild dish soap.
- Rinse thoroughly so no soap residue remains.
- Air-dry completely before putting it back.
- Cleanable tubs only: you can wash it on the top rack of the dishwasher instead.
Avoid: bleach, harsh chemicals, scented soaps, abrasive scrubbers, and putting a standard tub in the dishwasher. These can warp the chamber or damage the seal.
If white mineral film starts building up, a switch to distilled water usually stops it from coming back. Once the film is stubborn or the chamber looks cloudy, it’s time for a replacement.
When should you replace your water chamber?
Most users replace their water chamber about every six months. Replace it sooner if you notice:
- Cloudiness or a white film that won’t wash off
- Cracks, pitting or scratches in the plastic
- A lid or seal that no longer closes tightly
- Leaking around the base
- A loud or whistling sound from the chamber area during therapy
See the full replacement schedule for every CPAP part →
Water chambers are replacement parts and don’t require a prescription.
Water in your hose instead of the chamber?
If you find water collecting in your tubing or mask rather than staying in the chamber, that’s condensation (often called “rainout”). It’s not a chamber problem. A heated hose, a tube cover or a slightly lower humidity setting usually fixes it. Here’s how to stop water in your hose →
At MyCPAPZone: [CONFIRM — which chambers are stocked: HumidAir standard and cleanable for AirSense 10, HumidAir 11 standard and cleanable, any React Health or Resvent chambers.]
Frequently asked questions
Does the AirSense 10 water chamber fit the AirSense 11?
No. The AirSense 11 uses the HumidAir 11 tub, which isn’t interchangeable with AirSense 10, AirCurve 10 or S9 chambers.
Is my CPAP water chamber dishwasher safe?
Only the cleanable version. Standard ResMed tubs are hand-wash only. On AirSense 10 tubs, “HumidAir C” marks the dishwasher-safe version.
Can I use bottled or tap water instead of distilled?
Distilled water is recommended. Tap and many bottled waters contain minerals that leave deposits in the chamber and shorten its life.
How often should I clean my CPAP water chamber?
Empty and air-dry it every morning, and wash it with warm, soapy water once a week.
How often should I replace my CPAP water chamber?
About every six months, or sooner if it becomes cloudy, cracked, or no longer seals properly.
Why is there white residue in my CPAP water tank?
That’s mineral build-up, usually from tap water. Switching to distilled water prevents it. A chamber with heavy build-up is best replaced.
This article is general consumer information about CPAP equipment care. It is not medical advice. Always follow your device’s user manual.