Electric heating / hot water tank, what is best system going forward?

get rid of storage heaters if you can afford, hw tank life dependant on scale build up but generally 30years+. you may want to upgrade your hw tank to either a combination cylinder or pulsacoil but if it works for taps i would suggest your shower is essentially and electric pump and that needs replacing!

To give you a good advice, one would need to really look at your set-up, at least as the power-shower is concerned: - what water feed does it have - too many bends, valves, etc. on it, - what static and dynamic pressures will your mains give you, - is there a pressure regulation valve installed somewhere, - or are you running off water-tank, - is it just a low wattage appliance (9.5KW shower will give you more than plenty of hot water but will need a higher rate cable and a CB than a 5.5Kw one(!!!), which gives you only a moderate amount of hot water but uses less electricity) Your storage heaters accumulate heat over night when the electricity is cheaper (you probably find out that you have a dual tariff), and ventilate it during the day. So, regarding the running costs over 24 hour use, you are better off now then if you were to change them for simple electric radiators and use them during the day when the electricity is more expensive. If you use hot water regularly and in large amounts, you probably want either new higher volume electric HW cylinder or HW storage vessel (the latter will give you less trouble with scaling and consequent need to change elements, but will be a bit more expensive) I hope you are at least a bit wiser now.