Hi and thank you for the advice but I may have solved the mystery to why I was seeking advice on my own separate water supply to my flat.
A few months ago everyone except my property was disconnected from the water tanks in the attic but my bathroom water supply was always on the mains water feed where as the rest of the flats were connected to the water tanks and there are 2 flats below me.
The factor decided to disconnect the rest of the flats and now everyone is on mains for the bathroom and kitchen.
Ever since they did work (I won't name and shame the company) but I started to get very sore skin, skin from my hands, face, started to peel till it was pink and burn sometimes it was seeping with fluid as I was itching so much. I thought I had developed psoriasis or had a become allergic to something and the GP was puzzled too. I honestly didn't want to get up out from bed because I couldn't hide it, skin layers peeled and patchy circles appeared. It all started when work was done in the attic and I decided to call out a professional and assess what work was carried out and would really appreciate your help/advice on this.
The expert with over 30 years experience checked everything and saw that my mains water pipe had not been touched (it is still an old 15mm pipe) however the rest of the neighbours all got new separate copper pipe work (22mm) with PRV's fitted.
But then he looked at my property's pipe from another side and saw that a part of the pipe which feeds the cold water feed to my bathroom had been cut off and joined with a pipe tee to my ground floor neighbours bathroom water supply. There are no check valves, PRV or NRV, the company saw that my property was already connected to the mains supply and rather than doing a proper legit job, cut my pipe and joined it together with my neighbours and charged me a fortune for it. Now I understand why my bathroom supply started to have water flow and temperature fluctuations and the pipe work whistles when my neighbour uses their bathroom supply.
Therefore I suspect that is the reason my skin has been suffering ( I spent a few days in my friends home and guess what my skin cleared) and I would like to know can cross contamination or fluid risks happen because of this and what the problems can be caused by cutting my property pipe and sticking my neighbours onto it.
I am so glad I called someone to check it out and at the same time so angry that this happened. I would appreciate your advice because I want this issue resolved and will tell them to fix my properties pipe to what it originally was and never touch it again as I am a owner where as the rest of the neighbours are social tenants. Is it doable to tell them to provide another pipe water supply for the other neighbour and to restore the work on my pipe to what it was originally. I had no issues with my bathroom supply or skin until they decided to do a bad job.
Thank you so much and I would be happy to hear any advice on what I can do about this.