On Thu, 19 Jan 2006 22:59:35 +0000, Ragworm The Abominable wrote:
Hello Ed, thank you for you reply.
It's possible that the 3 port valve did not go fully to HW only before it
was repaired?
The spring went west, the motor got tired, and the shoe got gummed up,
I believe that the three way at this time is functioning from a
diversion point of view as it should.
So that's the probable cause.
The best by far if you can afford it and the boiler supports it is to go
for a sealed system. See FAQ.
I am considering this as a long term fix - it's a Keston Celsius 25
and I really don't think this boiler is happy unless it's sealed.
My own KC25 is sealed, but I'v down a couple of vented installs no
problem.
You could try putting a higher loop on the vent pipe so that it requires
a bigger pressure difference to start pumping over.
Planning to do this at the weekend - the better half got me the raw
materials, all I need to do is ensure I don't set fire to the loft. Any
'guesstimate's on whether I should make the loop as tall as the loft
roof, or go for something less
You could route the feed into the vent pipe - this will make refilling
the system harder but definitely fix the problem.
I could put a T-Junction join in the loft between the vent and the
overflow tank - or would the join need to be lower down in the airing
cupboard?
I don't think it will make much difference nearby is simpler and may lead
to less air locks.
You could try a lower pump speed and provided it still actually heats
the house and HW. It might also cause the boiler to kettle.
Unfortunately the pump is modulated directly by the boiler.
Now I know it's a KC25 indeed so. It will always use full powre and pump
when the primary circuit is cold.
--
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