On Thu, 23 Feb 2006 21:19:35 +0000, The Natural Philosopher wrote:

Ed Sirett wrote:
On Wed, 22 Feb 2006 21:49:37 +0000, Owain wrote:

Coldtoes wrote:
Our boilerman came round and checked the pump, which he said was
working. He diagnosed a blockage possibly caused by a build up of silt
and sludge in the system. Following his directions we used chemicals
(Sentinel) to clean the system out. ... On our second visit from
our boilerman he recommended a powerflush - but suggested one last go
with a different brand of chemical (Fernox). ,,,
It is possible that the sludge has killed the pump, the boiler has
overheated and cut out.

If the system has worked in the past it will probably work again, but it
needs a proper clean out. You can hire the powerflush machine and DIY or
alternatively take the radiators out into the garden and hose them out.
A new pump is usually quite cheap.

See Andy Hall's postings on this subject [1] and when he warns that
radiator sludge is indelible on carpets he means it :-)


This is a sick heating system.

I diagnose pump failure and/or serious sludge and corrosion.


I am not so sure. When I commissioned my system here , I had a huge
problem in getting some remote rads to actually fill with water at all.

The solution was to turn off (using the balancing valves).. all
radiators apart from the highest one that always seemed to trap air, and
the offending ones, and crank the pump up to 11...;-)

That finally blew the air out and back to where it could be bled properly.

Sorry, I rarely work on header tank installations now and I forget just
how difficult it can be to get the air out.


--
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