How to Descale a Coffee Machine (Step by Step)

General buying advice. Always check current specifications, prices and reviews with the retailer before you buy.

Limescale builds up inside every coffee machine, and in hard-water parts of the UK it happens quickly. A scaled-up machine heats slowly, makes weaker coffee and can break down sooner. Descaling is simple if you follow the right steps.

Check the manual first

Different machines need different descalers, and some have a built-in descaling programme. Check the manual for the recommended product and method, because using the wrong one can damage the machine or affect the warranty.

Choose a descaler

The safest choice is the descaling solution recommended by the machine's maker, or a descaler that says it is suitable for coffee machines. Some people use citric acid, but check the manual first, because it is not right for every machine.

The basic steps

Empty the water tank and any used coffee, then mix the descaler with water as the instructions say and pour it into the tank. Run the descaling programme, or run the solution through the machine in stages, leaving it to work for the time given in the instructions.

Rinse thoroughly

Empty the tank, rinse it, fill it with fresh water and run several full tanks through the machine until there is no taste or smell of descaler. This step matters, because leftover descaler can spoil the coffee.

How often to descale

It depends on how hard your water is and how often you use the machine. Hard-water areas need it more often, and many makers suggest every few months. Some machines tell you when it is time. Using filtered water can help slow the build-up.