Mike Mitchell wrote in message . ..
On Tue, 7 Sep 2004 09:34:46 +0100, "Christian McArdle"
wrote:

I have an airing cupboard, a hot water tank and my boiler has a pump.
How/why does the combi boiler get rid of both the latter?

The difference between the (instantaneous) combi and the non-combi boiler is
that the combi boiler has a heat exchanger that heats the incoming cold
water as you need it. It does this without any tanks or hot or cold water
storage. Advantages are that it uses the full mains pressure, so you get
excellent showers (assuming a reasonable water supply). Unfortunately, it
will heat only so much water at a time, so bath filling tends to be slow.
They are a good choice for houses where the bath is used infrequently, as
they are cheaper, smaller and more efficient than a storage based solution.

It gets rid of the external pump, because they almost invariably have an
internal one, making the external one redundant. Even most non-combi boilers
have a built in pump these days.

Christian.

Ah, right. I couldn't do without my baths, though! I lived with a
shower for 12 years (i.e. no bath) and the joy of a relaxing, piping
hot bath, especially on a cold winter's morning, is irreplaceable.

MM

There are higher water flow combi's around. The Alpha CB50 I mentioned
in my last post is one. The larger combi's fill baths as fast as any
storage system and are far easier to fit and get rid of tanks. I know
of a few higher water flow combi's and the owners would not have
anything else. Don't buy the small flow rate combi's, get a large flow
model if you want fast filling baths.