Depending on the frequency of use of your coffee machine, we are advised to clean the thermoblock circuit of our machine to remove the build up of coffee,scale & oils that collect over a period of time . The Sunbeam manual (or your manual for other brands of machines) lists all the instructions for this operation & I am amazed every time I use this product how much residue comes out of my machine when completing this operation. You can purchase tablets or use vinegar for this operation but vinegar does not clean as well & the tablets are more expensive by comparison so my choice is the descaling liquid by Sunbeam. There are other brands of liquid out there but when you compare the amount required to do the job of the other brands I have checked out the Sunbeam product represents the best value for money for me.
This operation is not to be confused with the cleaning of the Group head, group handle & filter baskets which is a separate operation & Sunbeam sell a tablet for this process & is usually carried out more frequently than descaling.