"Ed Sirett" wrote in message
...
On Fri, 09 Feb 2007 11:56:10 +0000, John wrote:

"Ed Sirett" wrote in message
...
On Thu, 08 Feb 2007 17:04:26 +0000, Roger Mills wrote:

In an earlier contribution to this discussion,
curiousdog wrote:

I have what I think is a conventional heating system (perhaps, maybe)
and have had several challenges over the years, must to do with the
motorised flow-control valve breaking.

More recently I have a concern with the pump. It's installed
vertically pushing against gravrity up to the valve where it splits to
the heating and the storage tank. On setting 1 it runs very quietly
but the pressure seems to be very low and the radiators don't really
heat up as they should. The water in the storage tank also takes
forever to re-heat. I am pretty sure there are no airlocks anywhere.

So, logically, I tried to set the pump speed to 2. The pump speed
picks up and makes a lot more noise and then stops and restarts
itself. There also seems to be a lot more noise in the pipes, water
sounds. But the end result of all this is a lot of air that I have to
keep\bleeding out every 15 minutes.

So, is the pump faulty?

I doubt it.


Should it be installed vertically pushing against gravity?



Mindset change required - consider it to be a "Circulator" rather than a
pump. The heating circuit is a loop - the "circulator is merely making
the
water flow around the circuit. The height of the system has no effect.

I disagree, at least in the way you have expressed it.
Where the feed pipe joins the circuit, the height of the header tank and
the position of the circulator within the circuit are absolutely crucial
to the correct operation or otherwise of the heating system.

Last week my apprentice and I fixed a system where the feed pipe had been
installed after the pump. We moved it to the right place but also had to
spend half a day powerflushing the system to remove (most of) the effects
of the misplaced pipe.


--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://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
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html
Gas Fitting Standards Docs he
http://www.makewrite.demon.co.uk/GasFittingStandards

I agree that there are many issues about vent pipes and feed pipes.