On 25/04/2012 20:51, kent wrote:
On Wednesday, 25 April 2012 20:42:01 UTC+1, wrote:
kent wrote:
On Wednesday, 25 April 2012 20:05:20 UTC+1, Jim K wrote:
On Wed, 25 Apr 2012 19:57:44 +0100, wrote:

This is probably a daft idea, but I'd be interesting to see if
there is any mileage in it! Combi boilers tend to work best in
smaller properties, so for a larger property would it be possible
(or make any sense) to have 2 combi boilers serving different
parts of the house? By "larger" I don't mean a mansion I mean a 4
bedroomed house with 3 showers!
Thanks for any thoughts on this.


ah the old ones are always the best....


nope! Thought of it all by myself! Is it that stupid then?

You have just made a new friend. He wll be along shortly to back you to the
hilt and claim you are a genius, second only to himself and Einsein.

--
Adam

Oh dear, I didn't mean to stir the s*** ! Does this mean I am unlikely to get any rational answers?!

No, you will probably get plenty ;-)

(There is/was a famous poster/troll/poet(bad)/legend in his own
lunchtime to this group who used to champion this particular solution
as a cure to every ill known to man).

So the basics; yes you can have two combis so long as the total demand
on your gas supply does not reach above about 60kW (assuming a normal
domestic meter). So a pair of 24kW ones is ok, a pair of 35kW ones would
be too much. (depends also on what other gas appliances you have)

You can have them completely independent of each other, but the only
real benefit would be the ability to position them so as to reduce the
time spent waiting for hot water at a tap, plus the ability to get some
heat and hot water when one goes wrong.

You could also merge their outputs together, but that then starts
getting slightly more complicated. It should alleviate some of the
problems with low flow rates of hot water that many of the less powerful
combis are famous for - but will ultimately be limited by the gas
supply, and so still won't be able to match other systems[1] if high
delivery rates of hot water are your goal.

On the downside, its a more complex system that may confuse some tasked
with maintenance, and you will incur two lots of service charges etc.

Also don't ignore the possibility of using one combi to heat a cylinder
of water as well as being able to provide hot water on demand itself.
(this can make sense where, one hot water outlet would be a long pipe
run from a main cylinder, and hence the combi can feed it directly, or
alternatively, when you have a gravity fed system that works well for
bath filling, but lacks pressure for showers.

[1] Some "other" systems would include the various hybrid
instant/storage combis, with built in unvented tanks of water cylinders.


Also see:

http://wiki.diyfaq.org.uk/index.php?..._Water_Systems



--
Cheers,

John.

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