Three pipes for cold mains - 1950s leasehold flat

[brokenbikeframe]

We are renovating our flat and are trying to sort out our plumbing.

We have three pipes that come from the ceiling that supply the mains cold water for all of the flats. Two 1 and 1/4 inch, and one 1 inch.

One 1 and 1/4 inch pipe supplies the hot water cylinder, the other supplies cold water to the bathroom taps (we think).

The 1 inch tap supplies cold water to the kitchen taps (we think).

Why would this be? We plan on replacing the conventional heating system with a combi boiler.

 

[denso13]

Why would this be?

Just the way it was done, quite common.

 

[Hugh Jaleak]

Suspect you have one mains feed, (going to the kitchen tap for drinking water and supplying the cistern in the roof), a gravity cold feed from the roof storage feeding the bathroom cold taps and WC, (not drinking water!), and a cold feed from above to the HW cylinders.

 

[Madrab]

Usually you would have one coming down to feed the bathroom with cold water, one my be the rising main up to the cistern in the attic. They may also be the feeds(s) to the flats below feeding their HW cylinder(s). You may also have a vent or two coming from the flats below heading up through the attic and roof.

Only way to really know is to track the pipes from the cistern in the attic to where they go ..... shut them off at the cistern to see what (if anything) it shuts off.