On Dec 12, 12:24 am, Andy Wade wrote:
Jimbo wrote:
One thing I've noticed is We have a small copper cylinder
(about 10 ins high and 5 ins dia) which when the central heating
switches off deposits a small amount of water back in the cold water
tank - It's got SPARTAN Automatic Recovery Tank on the side of it (and
Bray Thermal Systems) and has an even smaller cylinder, with a screw
on top, on the side of it (10 Bar max operating pressure)

Does this help? - copied fromhttp://forum.plumbingpages.com/hydro-spartan-help-vt6823.html

[Begin quote]
Hi, in response to your question, I worked in the Design & Technical
dept for Hydro Spartan when I left college back in the early 90's. The
company closed about 16 years ago but I kept some old brochures and
leaflets, which I still have. If you would like copies, please let me
know and I will scan and email them to you.

The Spartan expansion vessel came in 2 standard sizes, ET50 & ET100, the
numbers representing the water capacity of the heating system, that the
vessel could be used with. I think Spartan is an acronym for "Self
Priming Automatic Recovery Tank".

Basically the Spartan is in 2 sections, split top and bottom. Water from
the domestic side of the system is piped through one of the side
fittings, into the top chamber. In the middle of the top chamber is an
upstand pipe. Once the water level reaches the top of the upstand pipe
it overflows into the bottom chamber. The bottom chamber is connected to
the central heating system, this water from the DHW system is used to
fill the central heating system.

The functions of the Feed and Expansion Tank in a normal open vented
system, are taken care of within the Spartan. Basically the head of
water in the DHW header tank and the internal layout of the Spartan
prevent water in the 2 separate systems from mixing under normal conditions.

It's pretty simple, as long as the Purgomat (Automatic Air Vent), which
is connected to the bottom of the chamber of the Spartan is working ok,
it shouldn't cause too many problems, as there are no other
working/moving parts to worry about. I hope this is helpful, if you need
any more info please ask and I will try my best to answer them.
[End quote]

I'm wondering it this is the cause of my smelly water,
redepositing water from the CH circuit back in the cold water tank ?

So perhaps your Purgomat needs attention... :~)

Was Hydro Spartan started by a dog owner called Wallace, by any
chance?

MBQ