Where to locate new boiler?

[benaround3]

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

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[stonehouse]

Have you ever considered about buying a new Rayburn with a back boiler?

 

[benaround3]

To Stonehouse: No, seriously, we considered it and we are just not the Rayburn type. Even the previous owners had a second cooker installed.

 

[Hot&Cold]

I stress that these are all temporary arrangements to get a boiler in for this winter, before the house is remodelled

What will be the permanent arrangement Will there be more demand on the heating/hot water or drainage system ?

benaround3 as a temporary fix,you could consider a combination gas boiler with new pipework and radiators through out (dump/discard all the existing untested pipework and radiators) start new.
The temporary position would need to be discussed on site,it help to reduce your costs

The remodelled house should include a utility room to house the combination boiler which can now be used as a system boiler to heat an unvented hot water cylinder. try not to compromise on your heating-hot water system .

some people have a hate for combination gas boilers but they have their uses

Is there actually a live gas supply available ?. Upgrading the incoming mains water may be an idea also a cctv of the existing underground drains will determine if defects are present. something a project manager will be aware of

Only onsite investigation's can be relied on

 

[benaround3]

Thank you.
Eventually we plan an extension totalling 40 or 50% of the size of the house as it is, but it will still be mainly the two of us living there. On the other hand there is very little insulation so we may actually be able to reduce the bills by adding cavity insulation and more loft insulation.

 

[dilalio]

First things to consider when locating a boiler is where the flue will be sited and that the external parameters of this arrangement are within regulations, regarding building openings and boundaries etc; the gas supply line and route is also an important aspect, as is path to drain for condensate.

All other plumbing requirements down to installers ability and expertise rather than regs.

 

[hard-work]

Take what old&cold says seriously. A large flowrate, quality combi is the way. I will add, tee off the cold water mains after the stop tap (a full bore stoptap). Take this to the combi in 22mm pipe. Cold outlets one way, hot the other. Have nothing teed off this pipe - only exception being a cold supply to the shower(s), just before the combi's cold inlet - the the pressure raise or lower around the combi the hot and cold to the shower is affected equally. The line of least water resistance is to the combi. In a mains water setup, combi or unvented cylinder, shower is king, it should take priority of pressure & flow. Unfortunately few ever are piped up properly.