Recent content by lost_cause

There was an old wall flame boiler, gravity feed hot water with 28mm pipes into the top and bottom on one side of the boiler water jacket. The other side of the boiler had a 15 mm feed and return to the rads. There was a pump in the rad return. I've changed the boiler and now puimp the...

Sorry if this has been covered before - perhaps you could direct me to the item if it has. What is the point of the expansion pipe (in the primary side) which feeds back into the header tank? Surely pressure can't build up in the system any where because there is always a path to the header...