On 5 Nov 2003 06:56:40 -0800, (Danny)
wrote:

Yes the pipe is approx 3 inchs apart, with nothing but pipe between
them. The position of the motorised valve is correct, I assume the
gate valve located prior to the inlet on the HW coil was to control
the temperature inside the HW tank by restricting the water flow.

Probably, but it's a poor way to do it because there is no control to
prevent the tank from overheating when the CH is running.



The
HW tank also has an emersion heater (switched off at present) and a
thermostat located on top - this is set to 60 degrees


I'm not sure where the return pipe from the central heating connects -
I can't get to them without lifting half of my upstairs floor up!

OK, then I think we have to assume that it does the obvious thing and
rejoins the return after the cylinder.



The boiler thermostat is set to half way, because on anything more
cause the boiler to pop off.


What boiler is it BTW.?



I was thinking that I may have sludge in
my boiler - but the fact that the rads get hot really quick tells me
that the water circulation in my system is good, ie, not blocked.

Not necessarily. It can be that the heat exchanger is badly sludged
but allows some water through. Generally, when this happens, the
boiler sings or bumps when the burner is firing, or as in your case
the safety cut out operates.

But
the overflow of water into the FE tank leads me to think that the pipe
on the flow from the boiler is blocked just after the pipe which hangs
over the FE tank. Any comments on this?

Well it starts to look like it but I just looked back through the
symptoms in the whole thread.

I think forget the thermostat for the moment - the safety cut out is
operating for a reason. Either it's faulty or the water flow is not
what you think and there is localised heating when the burner fires.

Given this situation, I would focus next on making sure that the heat
exchanger really is clean. Since you already said that you had
sludging in the bypass and elsewhere, I am thinking that this is the
next area to look and I would do that before buying spare thermostats
and cutouts.



What is a zone valve, and what are the controls to make my HW
connections more efficient?

It would be a two port motorised valve similar to the CH one, operated
by a thermostat on the cylinder. You then need to have appropriate
wiring with the boiler, pump and timer to hook it all together. I
would expect that the current setup that you have is very simply
wired. Have a look at the Honeywell web site and S-plan
configuration for two valves, or Y plan if you would prefer a single
divert valve. I wouldn't bother with this until the boiler issue is
resolved, though.







Regards,



(Danny) wrote in message . com...
Opp sorry, it should have been

http://dognet.no-ip.com/ch.jpg

Regards,


Andy Hall wrote in message . ..
On 4 Nov 2003 13:13:02 -0800, (Danny)
wrote:

Hi Andy,

I've sketched a diagram using word, its not too clevor but I'm sure
you'll see how my system is setup.

Visit http://dognet.no-io.com/ch.jpg

My boiler is just a standard traditional one

I've located the manual lever on the motorised valve and operated this
whilst the cover was removed, it sounded free from obstruction, the
cogs inside were turning. However when I let go the vavle returned to
the starting position and then a small amount of water came out of the
FE tank. Is this relevant to your diagnosis?

Regards,


Danny, is the URL correct? I am not getting this as a site that
exists (no domain name).......


.andy

To email, substitute .nospam with .gl

..andy

To email, substitute .nospam with .gl