Indirect copper cylinder replacement

Can any of you guys out there in the uk give some advice about a suitable replacement for an indirect heated copper cylinder please.

I don't yet want to replace my existing cylinder yet but I do want to be prepared with a product when the present cylinder inevitably leaks. I have an existing Vulcan continental boiler that I wish to continue using (until it wear out after which time it will probably be a condensing boiler) and I have a very powerful power shower with 4 body jets manufactured by Aquilisa which empties all the hot water in under 5 minutes, and a theoretical emptying of my 50 gallon roof storage tank in under 12 minutes given half a chance. This high flow rate ensures that instant domestic water heaters would be inadequate. My copper cylinder has an electrical immersion heater, which I would like to preserve as an insurance policy against boiler failure. Here in lincolnshire we have got the hardest water in the country. Obviously the new copper cylinder replacement will be a larger volume and be ready lagged but has anyone got any ideas on replacement hot water storage devices that are hard water tolerant and can incorporate electrical heaters for fitting in an airing cupboard? Links to websites would be appreciated.

If your mains water supply is up to it, then I'd suggest a large heat bank. These would not require any loft storage at all, so you can't ever run out of supply water. They are also available in large sizes, so you can shower for longer before the water goes cold. The higher internal store temperature than a conventional cylinder gets more energy storage per unit volume.

With such a system, you won't need the noisy, unreliable pump, either. You connect the panel shower directly to the hot and cold water supply. Obviously, if the pump is internal to the shower, you may need to check compatibility with Aqualisa. It might still be possible to disable the pump, but you mustn't run the system pumped whilst connected to the mains. If the pump is something like a twin impellor external pump, then there shouldn't be a problem, provided you check your mains supply has sufficient flow rate to match the manufacturer's recommended supply.

You should go for pretty much the biggest heat bank you can fit in the space available, by the sounds of it. A "standard" hot water cylinder is 120 litres. A 180 litre heatbank will give more than 50% extra capacity. DPS do them all the way up to 500 litres, which would suit a small hotel.

formatting link

They are relatively simple DIY fitting, provided you know how to make solder and compression joints and use a pipe bender. Obviously, if you have a old low powered non-modulating boiler and a huge heatbank, then recovery times might not be great. With a replacement modern condensing boiler, they should be pretty good. It would take most of the day to totally replenish a huge heatbank with a 3kW immersion, although they are happy to install extra heating elements if electric recovery is likely to be required frequently.

Christian.