Do I Have To Use Distilled Water With My CPAP Machine?

November 09, 2018

Do I Have To Use Distilled Water With My CPAP Machine?

A popular topic we often get asked is about water: Do I have to use distilled water with my CPAP machine? What is distilled water?  Can I use tap water? Or spring water? What is the difference? Do I have to use distilled water when I'm travelling? 

Learn the difference between types of water available and what you should use with your CPAP machine. 

CPAP manufacturer Resmed (who makes AirSense 10 and S9s) recommends filling your water tub with distilled water to maximize the tub's lifespan. Respironics (who makes DreamStation and Remstars) recommends using distilled water in your humidifier to avoid mineral deposit buildup.  We recommend CPAP users to follow the manufacturer's user manual for the optimal performance of their products.

Types of Water

Distilled water is water that has been boiled into vapour in one container and collected back into liquid form in a separate container. This distillation process filters impurities behind when the water evaporates. This removes microbes and minerals like calcium and magnesium. 

Springwater is water filtered naturally (by rocks) and contains minerals. 

Tap water is water containing solutes like chlorine and fluoride and also contains minerals. 

The difference between the types of water would be the presence of minerals, microbes, organisms or chemicals. 

Tap Water & Your CPAP Machine

As mentioned previously, if your CPAP manual says to use distilled water, stick with distilled water. Water in other forms can mineralize, harden, discolour and scale your water chamber with time.  That being said, we have seen CPAP users use tap water - it decreases their product's lifespan and increase the frequency they need to replace their tubs. Make note of your water chamber's life span and replace as recommended by the user's guide. 


A key consideration when travelling is the quality of water. If you don't trust the water supply, don't use the water in your CPAP machine. Find access to a drug store or a pharmacy where you can purchase distilled water. Using distilled water in these instances will minimize your exposure to any risks. Some CPAP users temporarily use bottled water until they find distilled water.

Finally, if accessing safe water is an issue when on the road, consider forgoing the usage of your humidifier until you get back home.     

Leave a comment

Comments will be approved before showing up.

with ResMed Airsense 10 machine or package purchase.

($16 value, while quantities last!)