Bought this 3 years ago to use in a holiday home, so only gets about 3 months use per year. Very disappointed that the battery on the indicator on the lid seems to have expired already, and apparently is non-replaceable. It seems very "non-environmentally friendly" to have to replace the whole jug just so I can return to having a working indicator, which I would prefer. I now have to wait until I can already taste unpleasant limescale in my tea, or notice deposits building on the kettle, before I realise the filter needs changing.