Hi Mr Bell, thank you for leaving a review. There could be a few reasons why that may be. Firstly, is it possible that you could have a small leak somewhere? It could be that your water supply has changed and the local water board is now pumping in water from a new area and the water could be harder than before. Or, that the unit is may need adjusting, if that is the case, call the dealer that installed it for you and they can come and have a look for you. If you would like to speak to our technical team our number is 0800 056 86 86. Thanks, Kinetico UK