Why is there water in my cpap mask?

If you’re a CPAP user, waking up with water on your face can be a truly disturbing experience.

Half awake, you start worrying that something is wrong with your CPAP. Don’t be alarmed. This is a fairly common problem known as rainout.

What is rainout?
What are the consequences of rainout?
How can you deal with rainout?
Related links and products

What is rainout?

Rainout is something that only occurs when CPAP users have a humidifier attached to their CPAP machine. When the temperature of the room is colder than the temperature of the humidified air traveling through your CPAP tube, water condensation builds up on the sides of the tube. The water will then drip onto the user as it exits the tube—essentially raining on you.

What are the consequences of rainout?

First and foremost, rainout can wake you up when dripping on your face, but it also has other consequences as well. These include:

Noisy sleep therapy: The moisture in the tube can cause a variety of unusual noises during the night, from gurgling to banging as the air pressure flows down the tube full of droplets.
Mold growth on CPAP supplies: Your supplies become less sanitary if not dried out properly after your CPAP session ends, as the waiting moisture is a breeding ground for germs and molds.
Shortened lifespan of equipment: Moisture leftover from rainout can even lead to your supplies degrading faster, contributing to small holes in your tubing that are hard to notice.

How can you deal with rainout?

Customize your humidification settings.

The main cause of rainout is the difference in the temperature of your room and the temperature in your tubing. The ResMed AirSense 10 AutoSet, Respironics DreamStation and F&P Sleep Style prevent rainout with their climate control functions:
- Automated Climate Control: Adjusts the humidity level of your water chamber and the temperature of your heated hose to match your room’s climate
- Heated Tubing: Controls the the moisture levels and the air temperature in your tube
- Tube Drier: After using your CPAP, a snowflake symbol will flash and the machine will dry out any moisture that remains in your hose
Upgrade to a heated tube.

If you don’t already have a heated tube or yours is defective, consider also purchasing a new one. The heating function will keep water droplets from forming inside the tube and prevent rainout from happening. Find your tube here.

When CPAP supplies don’t function as well as they used to, replacing them is the quickest and most effective solution. Private health insurance covers replenishment parts yearly.

If you already have a heated tube but you’re still experiencing rainout, you probably need to manually adjust the settings. Below find out how to adjust for each CPAP machine we carry:
Shop heated tubing
Insulate your tube with a tube cover.

If you don’t have a CPAP machine compatible with a heated hose yet, then a tube cover can help lower the amount of rainout that occurs. Tube covers provide an extra layer of protection between the temperature in your room and the temperature in your tube. This helps keep rainout down by insulating your tube from your room’s cool air that would otherwise condense the water vapour in your tube back into droplets.

Shop tube covers
Make sure you’re cleaning your CPAP.

Water buildup can restrict airflow from your CPAP, but rainout isn’t just a problem that prevents you from having a peaceful night’s sleep. If you aren’t cleaning your supplies every day, the moisture buildup can allow bacteria and mold to grow in your CPAP tube. The Lumin CPAP Cleaner will sanitize your equipment and prevent you from breathing in those harmful particles.
- One-click cleaning: Just press a button and let the Lumin do the rest
- Completely compatible: No adapter needed to use with any mask and machine
Shop the Lumin