You must be the other white meat . <| sep |> There is no such thing as maintenance free equipment . There is only equipment designed to last 10 years and 2 months when neglected by it ' s owner . I bet if you look in the manual , it probably requires regular chemical descaling . The ones I ' ve seen sure mention descaling . I ' m not sure how else you ' d prevent your heat exchanger from getting covered with limescale . Gas Tank heaters don ' t scale up so much as they fill with sediment , which can be flushed out by opening the TP relief valve for a minute to stir everything up , then draining 5 gallons out the bottom drain tap . I ' ve honestly never used an electric tank heater , but I ' d imagine their heating elements can scale up quite easily as well , just like every single other resistive heating element I ' ve ever seen heating water . I suppose it ' s kind of the devil you know vs the devil you don ' t but I ' ve tried to remove limescale from steam humidifiers and it is a horrifically labor intensive task . I can ' t see a high efficiency heat exchanger dealing well with limescale , and I can ' t see removing it as an easy job . Tanked heaters generally fail when the owner does not replace the sacrificial anode rod inside the tank . Once the anode rod is used up , the tank pressure vessel starts to corrode and you get a leak . Change your anode rod regularly , and you should get 20 years out of a tank water heater instead of 6 or 10 . By the way , I quite enjoy learning about how europe is doing this stuff and the problems they have with their own gear . Thanks for informing me !