On 06/01/2012 11:57, Lieutenant Scott wrote:
On Thu, 08 Dec 2011 11:25:19 -0000, John Rumm
wrote:

On 05/12/2011 21:46, Lieutenant Scott wrote:
On Mon, 05 Dec 2011 15:43:30 -0000, thirty-six
wrote:

On Dec 5, 3:11 pm, "Lieutenant Scott" wrote:
On Mon, 05 Dec 2011 14:20:06 -0000, thirty-six
wrote:
On Dec 4, 11:42 pm, "Lieutenant Scott" wrote:
http://diydata.com/projects/centralh...diator_balanci...



Why? Surely if your boiler is powerful enough you don't need to
mess around like this. If your boiler can't heat all the radiators at
once, your boiler is too small for the system. Even with all my
radiators on full blast, the boiler doesn't run continuously.

I suspect then you have a microbore (8mm, 10mm) sealed system
radially
distributed by a central manifold.

Of course. Do you mean to tell me that the large bore systems don't
have a correspondingly larger bore pipe from the boiler to feed them?
What ****t designed that?!?

Do you know anyone using a large bore system in a small house? Do you
alternatively mean minibore (22&15mm)? I would rather you get your
terminology in order before hurling insults.

Large in comparison to microbore ffs. You know perfectly well what I
meant. So, answer the question, do you have a larger diameter pipe from
the boiler than to each individual radiator? If not no wonder you need
to do the silly balancing act.

Modern systems are usuually plumbed in a mixture of 22 and 15mm pipe.
The upper practical limit on the power transfer of a 15mm pipe is around
6kW, so that alone would not be adequate for a whole system, however is
usually ample for a small number of rads.

Balancing is not by any stretch "silly" and is understood by all but the
most clueless of installers to make a system work better.

It's a workaround for a poorly thought out system.

Even well thought out systems usually need balancing to get the best
from them.


So why have I never had a problem? I drained the system years ago and
never put inhibitor back in.

Define "problem". A system without inhibitor will corrode faster than
one with it. How fast, and what the consequences of that corrosion will
be however are variable.

A clunky old boiler such as yours will care less about dirty primary
water than will a modern HE boiler[1].

[1] Modern boilers have primary heat exchangers with a greater number
fins, and narrow water pathways to increase the overall surface area.
Needless to say these are more prone to blocking by sludge, and erosion
by particulate debris in the primary flow.

So my boiler is actually better! Cool.

Better in the sense its less fussy about running in a dirty and poorly
maintained system. You pay for that in lower efficiency though. So you
pays your money and takes your choice...

Even a badly corroded system can
seem to be operating well right up until the point the rads start to
pinhole, or sludge build up starts to inhibit performance or cause a
blockage.

Fix it when and if it happens. Anyway the nice clean Scots water will

Its an expensive fix at that point...

not do that so fast. And when I've removed a radiator (for renovations,
nothing to do with the heating), the water in it was perfectly clean.

The source of the water in the primary circuit has very little to do
with it. The sludge does not come from the water, it comes from
corrosion of the system itself. In hard water areas there will be a
small amount of scale deposited - but this only happens each time the
system is refilled. Once the scale has precipitated out, there is no
more to deposit.

The place the soft water will be of benefit is on the DHW side of a
plate heat exchanger on a combi. It will stop that bit scaling. The does
not prevent the primary side from getting blocked by rust or sludge though.



--
Cheers,

John.

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