"Christian McArdle" wrote in message
. net...
The point is, cost is an issue for me as is speed of installation, I
am hoping to be able to do everything over the coming weekend and
still have hot water by Sunday evening (and without missing the
England game).

The heatbank is plumbed in exactly the same as a combination cylinder,
except for the following differences:

1. You need electrical power for the pump.
2. The cold mains feed goes to an outside tap with hose attached, rather
than to a ballcock valve.
3. No overflow is needed.

Basically, you have cold mains in, hot water out, flow and return to the
boiler and that's it. Other things, like cylinder thermostats and zone
valves are the same for both types.

It is actually easier to install than the combi, as electrical power is
probably easier to source than an effective overflow.

The main problem is the cost, which is much more than a combination
cylinder. However, against that is the fact that the showers can use
simple
cheap thermostatic mixers and don't need noisy, expensive or unreliable
pumps.

An Albion 1200x450 Indirect Combi goes for around 250 quid. This has 115L
hot and 40L cold storage. (No sign of the 80L standard according to IMM).

Look at Range.

My 180L DPS Pandora cost 750 quid, although I could probably have beaten
them down a bit if I had any negotiating skills. Obviously a 180L heatbank
will annihilate a 115L gravity cylinder in every respect, but it is
definitely the more expensive option, although it compares favourably with
an unvented cylinder, especially when installation costs are considered.

If you look at the real cost of ownership, the difference isn't so clear.
You should consider:

1. The fact that a copper cylinder with constantly fresh water will last a
fraction of the lifetime of a heatbank filled with corrosion inhibited
water.

2. You don't need expensive, noisy, unreliable pumps if you want a shower.
(Gravity showers are fine if your idea of a shower is a dripping tap).

Venturi showers can be used.

3. Filling is manual, so a leak (except in the mains pressure feeds, of
cour
se) doesn't result in an unlimited discharge of water. They also do
automatic fill versions if you don't care about this possibility.

4. If the heat exchanger does scale up, it is simple to descale without
replacing the entire cylinder.

You'll need to be quick if you want it installed by Sunday, though.
Although
I understand that DPS now hold stock of popular items, delivery in such a
timescale might be problematic.

Christian.