On Wed, 05 Nov 2003 09:33:48 +0000, Andy Hall wrote:

On 5 Nov 2003 00:40:50 -0800, (Danny)
wrote:

opps sorry, its

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




Hmm.....

This doesn't seem to be quite as I'd expect.

Are you saying that the two pipes to the FE tank are 3" apart on the
flow pipe coming from the boiler? i.e. the amount of flow pipe between
the branches is only 3"? Normally if the distance between these two
pipes is less than about 6", and there is nothing other than pipe
between them, there should not be pumping over......

Are you sure about the arrangement of where the motorised valve is
located? This doesn't seem right somehow because there is then
nothing to control the operation of the hot water. Is there a
thermostat on the cylinder?

Also, can you indicate where the return pipe from the CH
connects......

There are certainly a few funnies that ought to be corrected and
improved (e.g. putting in a diverter valve or zone valve for the HW
and better controls). However, I can't see anything that obviously
leads to low temperatures from the boiler. Short cycling where the
boiler comes on for a very short time and then off, would be a symptom
of poor flow or something related to it. However, if the boiler
runs for several minutes and then turns off with its internal
thermostat, it is most likely that the thermostat is the culprit. Is
the thermostat set to full, and is the temperature of the flow less if
you reduce it?

Would others like to comment here?


This looks like a very typical arrangement for an older system and
correctly laid out.
It does not have fully independant control of CH and HW and HW temperture
is set by the boiler's thermostat.


--
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