A water filter helps reduce substances and minerals in the water entering your coffee machine. Depending on the filter system, this can include reducing the minerals responsible for limescale as well as improving the taste and quality of the water used for brewing. Because water makes up most of every cup of coffee, its quality can have a noticeable effect on both the drink and the machine.

Yes. One of the main reasons for using a compatible water filter is to reduce the amount of scale-forming minerals entering the machine. This can slow limescale accumulation within the heater, valves and internal water circuit. A filter doesn't make the machine completely immune to scale, however, so descaling should still be carried out when required.

Not necessarily. A correctly fitted and regularly replaced filter can significantly reduce limescale build-up, but its effectiveness depends on factors including water hardness, usage and how regularly the filter is changed. Follow your machine's maintenance reminders rather than assuming that fitting a filter removes the need for descaling altogether.

It can. Coffee is predominantly water, so unwanted tastes or odours in your water can carry through into the finished drink. A suitable water filter can improve the quality of the brewing water, helping the flavour of the coffee come through more consistently. Good water quality is therefore about more than protecting the machine from limescale.

Yes. Hard water contains higher levels of scale-forming minerals, so machines used in hard-water areas can accumulate limescale more quickly. Using the correct water filter can help reduce the amount entering the machine, although the filter must be replaced when required to remain effective. Setting the correct water-hardness level on your machine is also important where this option is available.

A water filter has a limited working life. As it becomes exhausted, its ability to treat the incoming water reduces and it may eventually restrict water flow if left in service for too long. Replace filters at the recommended interval and correctly prepare or prime the new filter before installation. If water flow becomes noticeably weaker following a filter change, check that the new filter has been prepared and fitted correctly before investigating a machine fault.