On Sun, 28 Nov 2004 08:39:08 -0800, Jasper wrote:

I have a cylinder that provides the hot water for our flat. Recently, we
noticed that the overflow was dripping o some work on the ballcock is
required but on looking at the cyclinder I am unsure if we dont also have
an additional problem as physically it looks as though there is a slight
leak.
To keep things simple and safe I would like to remove the cylinder and
replace it but I am struggling to "identify" the type of cyylinder I have.
This may seem strnage but the cylinder appears to be in two parts. THe
main unit appears prety standard and contains two seperate heater
elements. Interestingly though, there is what I think is some sort of
"header" tank that sits on top of the main cylinder and contains cold
water as well as the ballcock and the overflow. This tank is also open to
the elements. The water in this tank is never anything but cold, it is fed
directly from the mains. THe cold water suply as one would expect is
direct from the rising main and both the cold supply in bathroom and
kitchen are fed from the main, not via a tank as best as I can tell.

My question(s) firstly, what type of cylinder do I have and are
replacement cylinder easily found? (The property is approximately 15 years
old). Is the "extra" tank a header tank as I assume and is it only feeding
the cylinder beneath? Is this really some form of gravity fed system or is
the main cylinder sealed and the hot water supply is under pressure (the
hot water supply presure is poor at the best of times but all propertiues
in the development seem to have this issue??)

THanks for any help!

Jasper

You didn't say that your hot water is all electric, but I assume it is by
your description.

You have a mains fed hot water tank (my last flat had a square one, but
IMM proffered a link to an equivalent round type).

The HW tank is electrically heated by (usually) 2 immersion heaters - the
lower one for the bulk of the water, from Economy 7, and the top heater is
a day top up heater.

The reason to have the funny little cold water tank on top is so that the
freshly introduced cold water can be fed into the bottom of the HW tank
via a pipe so as not to intermix with the hot water stored any more than
possible. The hot water floats on the cold as usual and is drawn off near
the top.

You definately have a leaking ballcock - it's no more difficult to change
these than any other types so dive in with your spanner and get it out

What evidence do you have of other leaks? It would be fairly unlikely,
unless you have leaks around the immersion heater bosses.

HTH

Timbo

--
Tim Southerwood
Website: http://www.dionic.net/