On Thu, 09 Dec 2004 15:32:45 -0800, denbigh197 wrote:
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The design is the same as the Celsius 25 just bigger. It is not as
quiet.
The same money nearly gets you 2 C25s which space permitting would be
the
way I would go in future just because
a) there is in built redundancy.
b) 7-50kW output (cf 11-37kW).
c) quieter.
Unfortunately, the C25 doesn't have weather compensation. Nor does it
have two switched live inputs (dual flow temperatures for hot water and
central heating). The C40 has both these features and I need them both.
I accept these points.
Note that the C40 is set up for
using a 70C-50C design out-of-the-box so that you will only get 70 flow
when the weather is very cold outside. On mild days you may well find the
boiler wants to run at 50C (flow) even when the boler control is turned up
fully. This may or may not bother you. It can also be changed.
Since this is a sealed primary what does the 'top up' unit mean?
I was going to use it to add inhibitor to the heating system.
Is this essentially a built in funnel with a valve?
To quote from the HVCA's Domestic Heating Design Guide:
"The top-up unit is connected to the highest part of the system and is
fitted with a double check valve assembly and automatic air eliminator.
The unit, which has a water capacity of about three litres, is topped
up manually when the water level drops. It is also useful as an
indicator of leaks in the system. It should be connected either to the
return side of the radiator distribution pipework or to the return side
of the primary domestic hot water circuit.
The commissioning of the system is greatly simplified when a top up
unit is installed as initial pressurisation is unnecessary."
There is no way I'd choose to fill a large system 3L at a time when the
mains filling loop is connected.
As far as I can tell it will be useful for
adding chemicals when the system is empty or at least at zero pressure,
there is no way it will top up the system once it is pressured.
--
Ed Sirett - Property maintainer and registered gas fitter.
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