1 Day Ago
if the hot water cylinder is just providing water to the one shower and not connected to the rest of the hot water pipework then there is no complication.
or as suggested you could have a hot water cylinder for most of your hot water needs, being heated by the surplus electricity and additionally by the boiler as needed. as you have a combi you would need one tap connected directly,
it would all depend on how much power you would be getting to heat the cylinder and location of the boiler, cylinder in relation to the draw off points.
an unvented cylinder works of the mains water, so has a greater working pressure than a traditional gravity hot water cylinder and tank set-up.
best to get a couple of quotes from local engineers, see what they suggest as making best use of what you want to achieve.