We have just moved in to a 1950's house which has a central heating system previously heated by a coal fired Rayburn which has been removed..
We need to have a new boiler installed, but this may have to be in a temporary location as we hope to have the whole house remodelled and extended. It won't be a combi, we would be happy with an open vent system
From what I have found and tried to show via diagram, there appear to be two circuits that were branched together near the HWC, one circuit includes the feed and expansion pipes and is also used to supply one radiator in the upstairs w.c., the other includes the pump, HWC and remainder of the c.h. system. There was no control valve I could see, so the hot water might have been heated by convection with the pump switched off in the summer..
In the diagram, all the c.h. pipework is copper, only the direct hot and cold pipes have some steel runs shown in orange.
I don't know how the 3/4 pipework that is now blanked off was originally plumbed in the area of the pump and HWC.
Option 1a
We were thinking of locating a new boiler in what is now the upstairs w.c. as there is a convenient external side wall available. Eventually this w.c. would become an airing cupboard and a full upstairs bathroom built further back. Would there be any problems with the boiler being temporarily sited one floor above the hot water cylinder?
If the boiler was upstairs, could it be plumbed in to the system in the interfloor space at point A, where there is already 3/4 in pipe up to the w.c. radiator, the green T junctions at B changed to just an elbow with the pipework below redundant, and the feed and expansion cct joined from C to the pump and c.h. circuit at D?
Option 1b
Alternatively could the boiler from upstairs be plumbed via the loft and Tee'd into the green feed and expansion actually in the loft, or would this leave insufficient vertical distance to the top of the expansion pipe?
N.B. The gas supply is at the front corner with the mains water, so would have to be run presumably up to the loft and across. There is no gas inside the house yet.
Option 2
The other alternative would be to site the boiler in the kitchen corner near the gas supply and run pipework across the bedroom floor, should we nonetheless still try to simplify the system by combining the feed/vent circuit with the pump and c.h. circuit? But the drawbacks are this would mean a flue coming out of the front of the house, longer pipe runs, and importantly we know we would have to re-site the boiler eventually as we cannot get a HWC in the kitchen location, whereas if the boiler was upstairs we may not have to move it, at least not very far.
I stress that these are all temporary arrangements to get a boiler in for this winter, before the house is remodelled.