The limescale buildup can affect other things also: At the beginning of 2025 after returning from a road trip we noticed that after flushing the toilet when filling the cistern with water ready for the next flush the pump would cycle briefly a couple of times as if restricted ( like when you open a tap just a little bit ). I started a topic on here thinking it might be water in the pump hydrogen tank or a pressure switch issue. Someone kindly posted that it was a build up of limescale on the diaphragm under the pressure switch. Sure enough i followed his advice, stopped the flow of water, relieved the pressure, removed the switch ( 3 screws) and cleaned the rubber diaphragm which showed some light brown buildup on it. 5 minutes and problem solved ! In January it started again, followed the previous instructions and problem solved again. Anyone with a Hitachi pump who has noticed similar changes in pump/water supply would be advised to take a look. Other than a little “ hardening of the arteries “ on shower heads i wouldn’t say we have a limescale issue, only takes a little bit.
