Our electric shower has just gone for the second time in three years, this is mainly due to the fact that we live in a hard water area. We have one of those magnmetic water softener things and have been flushing the shower out with cold water after using every time but it still seems to give up after a year or so. We have a combi boiler (pretty new), don't know if the water system is high or low pressure. Would a thermostatic mixer shower be best? The main thing is, don't really want to spend alot of money!