A distiller is a countertop or under-counter appliance that boils water, carries the steam away from everything that could not evaporate with it, and condenses that steam back into liquid in a separate container. Because almost every dissolved mineral, metal and salt stays behind in the boiling chamber, the water it produces is about as close to pure as a household appliance gets, and that is both its strength and its limitation.
How the cycle actually works
Water is heated in a stainless boiling chamber until it turns to steam. Dissolved solids cannot follow it, so they concentrate in the chamber and eventually form a hard crust on the element. The steam rises into a condenser, usually a coil cooled by a small fan, and returns to liquid in a collection jug. Most units pass the condensate through a small carbon post-filter on the way out, which catches the light volatile compounds that boil at a lower temperature than water and would otherwise travel with the steam. The process is slow by design: a full jug takes hours, and it runs on mains electricity.
What comes out and what stays behind
Distillation removes dissolved minerals, most metals, nitrate, salts and the hardness that scales your kettle. Hardness is dissolved calcium and magnesium, and the USGS classes water as soft at 0 to 60 mg/L as calcium carbonate and very hard above 180 mg/L; whatever your figure, essentially none of it leaves in the steam, which is why the boiling chamber needs descaling. Boiling also kills bacteria and other microorganisms. What distillation handles least well without the carbon stage is volatile organics that evaporate near or below the boiling point of water, since those can carry over with the steam.
Distiller against reverse osmosis and filtration
Reverse osmosis gives comparable purity at a similar tap, produces water on demand rather than in batches, and needs no electricity to heat anything, but it wants adequate line pressure, a drain connection and a plumbed installation. A distiller needs none of that: fill it, plug it in, come back later. That makes it genuinely useful for renters, for a well household waiting on a treatment decision, and for anyone who wants a system with nothing plumbed in. The trade is throughput and running cost, since heating water is energy hungry and the appliance produces a jug at a time.
Living with one
The maintenance job is descaling the boiling chamber, and the interval is set by how mineral-rich your feed is. Left too long, the crust insulates the element, the cycle takes longer, and the element eventually fails. Rinsing the chamber after each batch and using a food-safe descaler on a regular schedule keeps it straightforward. The carbon post-filter needs replacing on the manufacturer's interval too, and it is easy to forget because nothing visibly changes. Distilled water tastes flat to most people because the minerals that give water its character are gone; some households add a remineralising cartridge for drinking, which our quote page can help you scope alongside other options.
Questions people ask about what is a distiller
Is distilled water safe to drink every day?
It is safe to drink, though it lacks the minerals found in ordinary tap water and tastes flat. People who dislike the taste often add a remineralisation stage after the distiller.
Does a distiller remove bacteria?
Yes. Boiling inactivates bacteria and other microorganisms, and they cannot travel with the steam, so a working distiller handles the microbiological side well.
How much water does a distiller make?
It works in batches over several hours rather than on demand, so most households use one for drinking and cooking water only, not for the whole house.
Does a distiller need plumbing or a drain?
Countertop models need neither. You fill the chamber by hand and pour from the collection jug, which is why they suit rentals and temporary situations.