Are these CH or HW pipes?

The ones that are looped are a 22mm and a 15mm. Same as mine. 15mm mains cold feed to the tanks in loft, 22mm for the gravity feed from cold tank to taps and immersion Cylinder.
Presumably if you’ve converted from conventional to combi, the 22mm will now be the cold feed to the boiler.
Thanks for this, it’s making sense now.
The combi boiler is fed via a 15mm that I can see coming straight off the main at the stopcock, which is on the opposite side of the room to this.

What’s bizarre is that on another thread I posted, the bath is fed by both a hot and a cold 22mm pipe that emerge from the floor, so they must go from 15 to 22 somewhere within the wall or the concrete floor, because I can’t see it anywhere!
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Evening all.

Just wondering if anyone can give me an idea what these pipes may be, please:

View attachment 284616

House built c1905. Concrete floor (rest of the house has floorboards).
These are within a kitchen cupboard that is against the party wall, roughly opposite the original kitchen back-door.

The boiler HW is a 15mm pipe but the downstairs bath hot and cold are both 22mm, those pipes emerging from the concrete floor (and leaving me scratching my head as to where it goes in to the floor and becomes 22mm!).

When I’ve run the hot water, none of these pipes feel warm.

Ideally I’d like to put an integrated fridge-freezer where this larder cupboard is, so I guess I’ll have to place the carcass on taller legs/plinth.

Any opinion welcome.

Just to update this:
The screwdriver-to-ear trick worked a treat, and I can now hear that the 22mm to 15mm loop is in fact the hot water feed, and the 22mm single is on the cold water feed.

Thanks all for the help and hints.


I can’t get a definite read on the remaining 15mm.

The pipes are somewhat in the way so I may see about abandoning them all and running a new hot and cold direct between main - boiler - kitchen - bathroom. If I don’t, at least I know what they could be used for
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