Getting started
CPAP First Night Setup: A Step by Step Guide
Set the machine on a stable surface below head height, fill the humidifier with the water type your manual specifies, connect the hose and mask, and fit the mask while lying down with the air running. Use ramp and exhale relief if they help, and expect the first few nights to feel strange.
Before bedtime
Unpack everything in daylight, not at midnight. Wash your hands, rinse the mask cushion and water tub once before first use as your manual directs, and check that the air filter is in place. The AirSense 11 guide and the DreamStation 2 manual both say to use the device only with the filter fitted.
Place the machine on a flat, stable nightstand, lower than your head if you can, so any condensation in the hose runs back toward the machine instead of into your mask. Keep curtains and bedding away from the air inlet.
Filling the humidifier
Fill to the max line only, and only with the water your manual specifies. Philips says to use room temperature distilled water in the DreamStation 2 tank. ResMed says the HumidAir 11 Standard tub takes distilled water only, while the HumidAir 11 Cleanable tub takes drinking quality water.
Never fill the tub while it is attached to the machine, and never move the machine with water in the tub. Spills into the machine can damage it.
Fitting the mask
Put the mask on, then lie down in your usual sleep position and start the air. Masks feel different under pressure, and a fit that seemed fine sitting up can leak when you lie down.
Tighten straps only enough to stop large leaks. Overtightening crushes the cushion and often makes leaks worse, and it can mark or break down the skin on your nose bridge. Many machines have a mask fit test in the menu: ResMed calls it Run Mask Fit and Philips has a mask fit check on the DreamStation 2.
Comfort settings to try
Ramp starts you at a lower pressure and builds up over a set time so you can fall asleep first. Exhale relief (EPR or Flex) softens pressure when you breathe out. Humidity and heated tube temperature can be raised for a dry nose or mouth, or lowered if water collects in the hose.
These are patient comfort settings and are fine to adjust. Your prescribed pressure or pressure range is not: changes to it go through your prescribing clinician.
If you wake up in the night
It is normal to pull the mask off in your sleep at first. When you notice, put it back on and restart the air. Every hour of use counts toward your benefit and toward insurance adherence rules.
If you wake up gasping, feel like you cannot get enough air, have chest pain or feel your heart racing, stop and contact your clinician. Chest pain is an emergency; call 911.
Checklist
- Rinse the mask and tub before first use.
- Place the machine below head height on a stable surface.
- Fill the tub with the water type your manual specifies.
- Fit the mask lying down with the air on.
- Turn on ramp and exhale relief if you want them.
- Keep the machine plugged in and the SD card in place.
Supplies that can help
Distilled water is what most CPAP humidifier chambers are meant to be filled with, because it leaves little or no mineral scale behind.
A simple hook or hanger for drying CPAP tubing vertically after washing, and for keeping it off the floor.
A pillow with cutouts or a contoured edge so a mask and hose are not pushed out of place when you sleep on your side.
Soft fabric liners that sit between your skin and the mask cushion to reduce skin irritation, red marks and the noisy leaks some people get from …
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Frequently asked questions
Should I use CPAP for naps too?
Yes, if you nap. Sleep apnea happens whenever you sleep, and usage during naps is recorded like any other session.
Why does the air feel too strong at first?
Air pressure takes getting used to. Ramp and exhale relief often help. If it still feels unbearable after the first couple of weeks, ask your clinician to review your pressure; do not change it yourself.
Can I use tap water on my first night if I run out of distilled?
Follow your manual. Some ResMed tubs are labeled for drinking quality water while others are distilled only, and Philips specifies distilled water. If your manual says distilled only, skipping humidification for one night is safer for the tub than using tap water.
How tight should my CPAP mask be?
Just tight enough to stop big leaks with the air running while you lie down. Red marks that last into the day, or pain on the nose bridge, mean it is too tight or the wrong size.
Sources
Last reviewed October 11, 2026. How we research · Report an error