Supplies
Heated CPAP Tubing and Rainout: How to Stop Water in the Hose
Rainout happens when warm, humid air cools in the hose and condenses into water that gurgles or splashes into your mask. Heated tubing keeps the air warm along the hose; lowering humidity, raising tube temperature, warming the room, insulating the hose and keeping the machine below head height also help.
Why rainout happens
Your humidifier warms and moistens the air. If the hose passes through a cooler room, the air cools and can no longer hold as much moisture, so water forms on the inside of the tube. It gets worse in winter, with air conditioning, or with high humidity settings.
Water in the hose can make gurgling sounds, spray onto your face, or wake you up.
Heated tubing
Heated tubes have a wire along their length that keeps the air warm until it reaches the mask. ResMed's AirSense 11 works with ClimateLineAir heated tubing, and its integrated humidifier can run manually or in automatic Climate Control. Philips offers a heated tube for the DreamStation 2.
With heated tubing you can usually run more humidity without rainout. Medicare's usual maximum for heated tubing (A4604) is 1 every 3 months.
Settings to try
If you have rainout: lower the humidity level a step, or raise the tube temperature a step if you have heated tubing. If your machine has an automatic climate mode, try it. Give each change a night or two.
If you have a dry nose or mouth instead: raise humidity a step. These are comfort settings you can adjust yourself.
Simple fixes without new equipment
Keep the machine lower than your head so water drains back toward the tub, not into the mask. Run the hose under your blanket or use a fabric tubing cover to keep it warm. Warm the bedroom a little if you can.
Do not overfill the water tub, and make sure the tub is seated properly.
Supplies that can help
Tubing with a built-in heating wire that keeps humidified air warm all the way to the mask, which is the main fix for rainout (water droplets …
A fabric sleeve that slips over CPAP tubing to insulate it, reduce condensation and make the hose feel softer against your skin.
A stand or arm that lifts the tubing above the bed so it does not drag on the mask when you turn over.
A simple hook or hanger for drying CPAP tubing vertically after washing, and for keeping it off the floor.
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Frequently asked questions
Why is there water in my CPAP hose?
Warm moist air is cooling in the hose and condensing. Lower humidity, raise tube temperature, insulate the hose or warm the room.
Is heated CPAP tubing worth it?
If you get rainout or want higher humidity, heated tubing is the most direct fix. It also helps in cold bedrooms.
Does a tubing cover stop rainout?
It can reduce it by keeping the hose warmer. It is a cheap first step, especially with standard tubing.
Can I use heated tubing on any CPAP?
No. Heated tubes are model specific because they plug into the machine for power. Use the tube made for your machine.
Sources
Last reviewed October 11, 2026. How we research · Report an error