"Lurch" wrote in message
...
On Wed, 14 Jan 2004 23:12:44 +0000 (UTC), "Michael Chare"
wrote:

"Anthony James" wrote in message
...
Christian McArdle wrote:

Are there any pitfalls I haven't thought of?
Secondly, ensure that you have a cylinder thermostat. It sounds like you
have an S plan system. If no cylinder stat is present, you need to insert
it
in series between the programmer "HW On" output and the hot water zone
valve
motor live (normally brown) wire.

Right. NOw you've lost me. Where can i find out what an 's' plan
system is? Why do i need a cylinder stat if i dont have one at the moment?

If you dont have a cylinder stat at the moment, my guess is that you have
gravity H/W. i.e. Your pump only drives the Central Heating.

If you would care to read previous posts you would note that;

a) there are 2 zone valves already installed, so that puts gravity out
of the question.

b) there is a cylinder stat etc... (see a))

Maybe I have paid more attention to the O/P's statement that he does not have a
Cylinder stat
than to your argument that he ought to have one.

Michael Chare