Is distilled water the same as deionised water? No. Distilled water is purified by boiling and condensation, while deionised water is filtered to remove charged ions. Both are highly purified, but they are used for different purposes.
If you are unsure which to buy, this guide explains the difference, common uses, and how to choose the right option for your home, lab, or business.
At The Somerset Clear Water Company, we produce both distilled and deionised water in-house at our Somerset facility, giving you UK-made quality, consistency, and purity in every drop.
If you are specifically choosing water for your steam iron, read our Best Water for Steam Irons guide.
⚗️ What Is Distilled Water?
Distilled water is made by heating water until it turns to steam, then cooling that steam back into liquid. This process removes minerals, salts, and many contaminants, leaving ultra-pure water suitable for delicate applications.
Benefits of Distilled Water
- Free from minerals and contaminants
- Stable and highly purified
- Suitable for medical, household, and technical use
Common Uses
- CPAP and humidifier machines
- Steam irons
- Car batteries and radiators
- Skincare and cosmetics
- Laboratory rinsing and testing
Learn more about appliance use in our guide: Why Use Distilled Water in Steam Irons?
⚡ What Is Deionised Water?
Deionised water is purified using ion-exchange resins that remove charged particles such as calcium, magnesium, and chloride. It is highly purified, low in mineral content, and widely used in technical, industrial, and cleaning applications.
Benefits of Deionised Water
- Removes ions that cause limescale and residue
- Ideal for glass, valeting, and electronics cleaning
- Efficient and practical for many technical uses
Common Uses
- Electronics and PCB rinsing
- Window and glass cleaning
- Car valeting and detailing
- Industrial washing
- Laboratory work where sterile water is not required
🧩 Distilled vs Deionised — Which Should You Use?
The right choice depends on the application. In general, distilled water is preferred for appliances, health-related devices, and situations where the highest purity is needed, while deionised water is often preferred for cleaning, valeting, and certain industrial uses.
Recommended Water Types
- CPAP machines & medical devices — Distilled water
- Steam irons — Distilled water
- Car batteries & radiators — Distilled or deionised water
- Skincare & cosmetics — Distilled water
- Lab testing — Depends on the purity required
- Electronics rinsing — Deionised water
- Window & glass cleaning — Deionised water
- Industrial rinsing — Deionised water
Quick rule: use distilled water for appliances and health devices, and deionised water for cleaning and industrial applications.
If you are also comparing boiled and distilled water, read: Is Distilled Water Just Boiled Water?
🇬🇧 Why Choose The Somerset Clear Water Company?
We do not just bottle bulk water — we manufacture it ourselves in Somerset. That gives you:
- Traceable, UK-made purity
- Consistent, high-quality batches
- Retail and trade supply options
- Fast nationwide delivery
Whether you need water for home, laboratory, or commercial use, you can rely on Somerset-manufactured purity and performance.
To learn more about product quality and authenticity, read our Counterfeit Distilled Water Warning.
For trade and industrial customers, we have also created a dedicated guide explaining how deionised water is supplied in bulk and used across laboratories, electronics manufacturing, and automotive applications.
🚚 Ready to Order?
Explore our distilled and deionised water in 5L, 10L, and 25L containers, shipped directly from Somerset.
Want to know more about buying options? Read our guide: Where to Buy Distilled Water in the UK.
Common Problems Solved with Distilled Water
Distilled water is not only useful for laboratories and technical applications. It also helps solve a range of common household and specialist problems where minerals in tap water can cause residue, limescale, or performance issues.
- White dust in humidifiers — If your humidifier is leaving a fine white residue around the room, minerals in tap water are usually the cause. Read our guide on using tap water in a humidifier.
- Limescale in appliances — Steam irons, garment steamers, CPAP machines, and similar appliances often perform better with purer water. See why distilled water is not the same as boiled water.
- Aquarium water control — Many fish keepers use distilled water when they want greater control over minerals, TDS, and water chemistry. Read our aquarium guide.
- Choosing the best water for humidifiers — If you want to compare tap, boiled, deionised, and distilled water for humidifier use, read our humidifier water guide.