On Sat, 08 Dec 2007 04:21:37 +0000, John Rumm
wrote:

Stuart B wrote:

reason .The rad in the hall with no TRV is not one that I have
actually touched since the boiler was installed in Feb 2007 until
tonight when I went to get something that was lying beside it ( stuff
I need for jobs I am doing round the house) so it might well have been
overlooked for bleeding when the boiler was put in and has remained
cold since .That might actually have been my fault as I bled some of
the rads and the installer did some so it could have been missed as
each of us thought the other had done it . .

It is quite possible it was bled, but more air collected in it after.
With a fresh fill of water it can take some days for all of the air to
come out of suspension. The other possibility is you have insufficient
(or no) corrosion inhibitor in the system and what you bled was hydrogen
gas produced as a corrosion by product and not air.


But would all the air be in only one rad if that was the case ?

There was sufficient inhibitor put in the system as I was there when
it was put in and know how much of the container he used .
Stuart