When the back pressure in my central heating rises, as the thermostaic
valves shut, I get pump-over. The height of the header tank is only a
metre or so above the top of the highest radiators. Can I safely
increase the effective head by raising the highest point in the
breather pipe? Any other ideas welcome. TIA.

On Mon, 17 Sep 2007 01:09:25 -0700 someone who may be
wrote this:-

When the back pressure in my central heating rises, as the thermostaic
valves shut, I get pump-over. The height of the header tank is only a
metre or so above the top of the highest radiators. Can I safely
increase the effective head by raising the highest point in the
breather pipe? Any other ideas welcome. TIA.

Far better to re-arrange the pipework so that the feed pipe and the
expansion pipe are connected to the suction side of the pump, which
is in the flow. That is how the pipework should have been arranged
in the first place. A search engine should pull up the proper
hydraulic arrangement of an open vented low temperature heating
circuit.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54