When it comes to CPAP care and respiratory health, few details are as important as using the right water. In this distilled water UK guide, we’ll explain what it is, why it matters for your CPAP humidifier, and where to buy distilled water safely across the UK.

Distilled water is purified by boiling and condensing steam, leaving behind minerals and impurities. It’s recommended for CPAP humidifiers because it prevents mineral buildup that can damage your machine or irritate your airways. Using tap water, on the other hand, may cause scaling, bacteria growth, or even unpleasant odours.
Most of our CPAP machines and accessories include humidifiers designed specifically for use with distilled water. This ensures the air you breathe is clean, moist, and comfortable every night.
Yes — a humidifier enhances comfort, especially if you experience dryness or nasal irritation. At Sleepap, we offer several CPAP and BiPAP machines with built-in humidifiers, combining quiet operation with effortless moisture control. This helps reduce the risk of dryness and “cotton mouth” while improving therapy comfort.
Learn how to use and maintain your humidifier correctly in our CPAP Humidifier Setup & Maintenance Guide.
If you can’t find distilled water near me, you can prepare it safely at home with basic kitchen tools:
Make sure your setup prevents contamination — never touch the inner collection surface during or after boiling.

For more information on how CPAP therapy works and why humidification matters, read our educational post CPAP Therapy: How It Works Guide.
“Cotton mouth” happens when airflow from your CPAP dries out your mouth and throat. To fix this:
For additional hydration and respiratory health tips, visit the Sleep Foundation’s CPAP Resource.
Using distilled water UK in your CPAP humidifier is a small step that delivers major benefits. It keeps your system clean, prevents scaling, and ensures safe, comfortable therapy. Whether you buy it from your local shop or make it at home, distilled water helps protect your CPAP machine — and your health — for years to come.
Do I need a humidifier if I use CPAP?
Yes. It helps prevent dryness and irritation. Sleepap offers machines with built-in humidifiers for effortless comfort.
Can I use tap water in my CPAP humidifier?
It’s not recommended. Tap water can leave mineral residue and cause bacterial growth inside the humidifier.
How to prepare distilled water?
Boil tap water, collect steam as it condenses, and cool it before use. This removes impurities and minerals safely.
Where can I buy distilled water near me?
Pharmacies, supermarkets, and medical suppliers across the UK offer distilled water — check for “100% distilled” labels.
How to prevent cotton mouth while sleeping?
Use a humidifier, adjust your mask fit, or add a heated hose to keep airflow moist throughout the night.