Most CPAP water chambers open by either sliding the tank out of the machine and lifting a flip-top lid, or by pressing a release button that pops the lid open. The exact method depends on your machine’s brand and model, but the basic steps are similar across devices. Here’s how to do it without forcing anything or damaging the seal.
General Steps for Any CPAP Chamber
Before you touch the water chamber, unplug the machine from its power source. If you’ve just finished a sleep session with heated humidification, give the chamber a few minutes to cool down so you don’t burn your fingers or warp the plastic.
On most machines, the water chamber sits in a bay on the side or back of the CPAP unit. Pull the chamber straight out, away from the machine body. Some models have a small latch or button you press to release it. Once the chamber is free, you’ll see a lid on top, usually hinged on one side. Lift or flip it open, fill with distilled water to the indicated max line, then close the lid until it clicks and slide the chamber back into the machine.
Opening by Brand and Model
ResMed AirSense 10 and AirSense 11
The AirSense 10 water tub slides out from the left side of the machine. Grip the front edge and pull it toward you. The lid lifts from the front, hinging at the back. To separate the lid completely for cleaning, gently flex the hinge tabs and pull the lid free.
The AirSense 11 uses a similar slide-out tub, but the chamber locks in with a slightly tighter fit. Pull firmly and evenly. The lid again lifts from the front edge.
Fisher and Paykel SleepStyle
The SleepStyle uses a simple button-press design. A single press of the button on the chamber opens the lid, making it easy to fill and clean. The chamber itself slides out of the base of the machine once you disengage it.
Philips DreamStation
The DreamStation chamber pulls straight out from the back of the machine. Once removed, you’ll see a flip-top lid with a small tab at the front. Press the tab and lift the lid open. The rubber gasket inside the lid can be gently peeled out for separate cleaning.
What to Do If the Chamber Is Stuck
If the lid won’t budge or the chamber won’t slide out of the machine, mineral buildup is almost always the culprit. Hard water leaves calcium and lime deposits around the seal and along the edges where the chamber meets the machine housing. Forcing it risks cracking the plastic.
Instead, soak the entire chamber in a solution of equal parts warm water and white vinegar. Let it sit for 15 to 30 minutes. The vinegar dissolves mineral deposits without damaging the plastic or silicone gasket. After soaking, try opening it again. You can also run warm (not hot) water over the seam where the lid meets the base to loosen things up. A soft cloth wrapped around the lid edge gives you a better grip without scratching the surface.
If the chamber slides into the machine easily but sticks when you try to remove it, check for mineral residue on the rails or grooves of the humidifier bay. Wipe those down with a damp cloth.
Filling and Reassembling the Chamber
Always use distilled water. Tap water contains minerals that leave white crusty deposits inside the chamber and can eventually clog the seal, making the lid harder to open over time. Fill only to the max line marked on the inside wall of the tank. Overfilling can push water into the tubing and toward your mask during the night.
When closing the lid, press it down until you hear or feel a click. A lid that’s not fully sealed will let moisture escape, reducing humidification and potentially causing water to leak onto your nightstand. Slide the chamber back into the machine until it seats flush. If it doesn’t slide in smoothly, pull it back out and check that the lid is fully closed and the gasket isn’t pinched or sitting crooked.
Keeping the Chamber Easy to Open
A quick daily rinse prevents the kind of buildup that makes chambers stick. Each morning, dump the leftover water, rinse the chamber with warm water, and let it air dry with the lid open. Once a week, do a deeper clean: wash the chamber with hot water and mild dish soap, or soak it in the vinegar-and-water solution to dissolve any early mineral deposits.
Check the silicone gasket or rubber seal inside the lid every few weeks. If it looks warped, cracked, or discolored, it won’t seat properly and can make the lid feel loose or overly tight. Most manufacturers sell replacement gaskets, and your equipment supplier can order one matched to your model. Replacing a worn gasket is one of the simplest ways to keep the chamber opening and closing smoothly for the life of the machine.