On 1 Nov 2003 06:25:40 -0800, (Marv)
wrote:



Anyway the point of my post, we have found a house we like but it has
a combi boiler installed (in the loft ?), dont know what make it is
but my question is, is it more than likely to still have the same
problems as this is how combi boilers work ? Also its currently a 3
bed house with 8 rads, we will be extending to make a fouth bed room
and bigger kitchen so that will probably be 10 rads in total. Would
this be to much for a combi boiler ?

It is typically not the heat output to radiators that is the problem,

There are three potential downfalls of a combi:

- Inadequate hot water production rate for the requirements of the
bath(s) and shower(s) in concurrent intended use. They are normally
specified with a rate in litres per minute for a temperature rise of
30 or 35 degrees. In cold weather when the water is at only a few
degrees above freezing, a shower (40 degrees) will be limited to
whatever the combi can do. Small ones with 9-11 lpm are going to be
disappointing.

Larger size combi boilers are available with outputs of 20 lpm or
more, although upgrade of the gas supply to the boiler may be required
if the pipe length is long or too small.

- Inadequate flow and pressure from the main, especially in an older
property. This can be measured at the kitchen tap. If you are
getting less than 20 lpm or so then results in general will be poor.
There are then two alternatives. a) Pay for the main to be upgraded,
which can be expensive. b) Install a conventional system with tank in
roof.

- Poorly implemented internal plumbing. This can be through re-use
of plumbing from an older roof tank/ gravity system providing
inappropriate distribution of water to the various taps and
appliances. It may be possible to correct this with flow
restrictors but often involves some replumbing or additional plumbing
so that feeds to certain locations are brought back to a common point.





If so then what are my options of removing the combi boiler and
replacing it with a conventional system ? Could everthing be placed
in the loft still ?

Yes it could. The appropriate solution would rather depend on the
limitations if any of the system.



Sorry for the long post, many thanks.

Marv.

..andy

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