Descaling your coffee machine regularly is required to ensure that the appliance works as intended. If you live in a hard water area, your appliance is more exposed to the damage of limescale and therefore your will need to descale it more often.
Solutions:
Descale the appliance using one of our tested and approved coffee machine descalers.
Insert a water filter to remove any unwanted impurities and materials.
Also ensure your appliance is being cleaned and descaled regularly to prevent a build-up of lime scale. You can find out descaling guide here.