What is hot water extraction and what is cold water extraction? Is there a difference and how does this compare to steam cleaning?

Firstly there seems to be confusion about the use of the word “steam cleaning” of carpets and upholstery. In order for something to be “steam cleaned” the water would need to be boiling hot and pressurised in order for a machine to produce “steam”. Often hot water extraction machines are confused with steam cleaning.

So what is hot water extraction? This is the use of warm to hot water that is taken from your tap at home which was heated by your geyser. The water and chemical is mixed in the machine and sprayed at high pressure onto your carpets and then extracted simultaneously.

What is cold water extraction? This is exactly the same method as above; only cold water from your tap is used mixed with chemicals.

There are many varying opinions regarding hot water vs cold water and steam cleaning. Firstly steam cleaning could be used for sanitising but it is not going to essentially clean and flush out all the impurities the way that water extraction will. The dirt will stay in the fibres. With regards to hot or cold water extraction the results will be the same in terms of removing the impurities from the carpet pile or fibres.

So does hot water sanitise or not? Well it depends on how hot the water is, according to some research it would also depend on what type of bacteria you want to get rid of. It would be almost impossible for a hot water extraction machine to produce or to get hot enough water from your geyser at home to be hot enough to kill all types of bacteria at 100degrees Celsius. Some fibres also shrink when using hot water. Some bacteria thrive in warmer conditions and may also multiply, so again the opinions are varied in terms of research done.

Does cold water sanitise? Cold water may not sanitise effectively as hot water but it would also depend on the type of chemical used and if that chemical has sanitising properties in it. As mentioned above, germs thrive in warmer conditions so it is in our opinion that colder water with a good sanitising and cleaning chemical should be used.

At weClean we use the cold water extraction method, where water and chemical is sprayed onto the carpet fibres at high pressure, the solution is then agitated by the carpet wand or brush in highly soiled areas. The solution of chemical and water is then sucked up by an industrial strength vacuum. The process is essentially flushing the carpet fibres clean of impurities. Our chemicals do not leave a sticky residue that some other powdered chemicals may leave behind which often causes re-soiling very quickly. Our chemicals also have sanitising properties.


We leave the decision up to you to decide which method would be best for your needs. However our advice is to go with a carpet cleaner that uses the water extraction method whether it is hot or cold water. Do some investigation regarding the type of carpets you have as some cannot withstand too much water such as silk rugs or shaggy rugs.