On Wed, 08 Dec 2004 10:08:36 +0000, John Aston wrote:


This is similar to a system I installed a couple of years ago. with a 170L
HWC and a Keston C40 (that's about 37kW output but runs at about 35kW due
to service main inadequacy). It works fine. Except I used a 5-way S-plan
and no UFH.


Ed, how do you rate the C40? I'm intending to buy this boiler and Keston's
Spa 300L cylinder.

We had a number of problems mostly that the gas valve kept getting choked
with a fine dust from the old 1" supply pipework (Yes I did blow the pipe
through before reusing it), replacement of thge pipe with new 28mm stuff
put an end to those problems.
After the first year when I removed the burner the top HE tube was
distorted which was replaced under warranty.

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.


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?




The water in the cylinder is heated indirectly by the primary of a 38kW
fully-modulating condensing boiler in the room below the cylinder. Hot
water
is circulated to the taps by means of a secondary pump. Because the
system
is unvented, the hot water is also at a pressure of about 2.5 bar.

Bronze pump needed will (cost will equal total of all the other pumps).
8-(


Thanks, Ed. Maybe I'll lay the pipe for the secondary loop and only add
the pump later if the dead legs are a big problem.

Well in relation to the multi thousand price ticket another £150 is not a
relatively big deal.

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html