Help needed figuring out water taps and valves in flat

[Sunshineray]

Good morning everyone,

New to the forum and looking for information to help me figure out plumbing work in my flat. I have provided details to give you an idea of what I may need and would be grateful for advice.

I live on the top floor of a 2nd floor flat in a block of 6 and the cold water is mains fed the hot is fed via a water tank in the building attic.
Flat is circa 1960s
25KW combi gas boiler, DHW is 25kw and heating is 20KWm (2 years old)
57 square metres flat
5 radiators in flat
1.0 bar pressure
Cold water has high pressure (mains fed) hot water is less pressurised (hot feed is via a tank in the attic shared by all those who live in the building)

• One red gate valve (main cold water feed) in a high cupboard outside and above bathroom door A stopcock under the sink on 15mm cold feed pipe and hot water pipe under the sink has a 15mm check valve on it Mains fed water but when I turned both stop cocks off the hot water still runs which makes me think that the attic or somewhere in the building must have a water tank.
• I did find another stop cock in the kitchen it is boxed in another wall near the bottom of the boiler pipes but when I turned it, it didn't do anything perhaps it was used when the old hot water system cylinder was used.
• There are two 22mm pipes in the high cupboard and cold water pipe has a 22mm NRV on it but not the hot one.
• The cold fills a 8 litre bucket in 20 seconds the hot 8 litres in one minute I have single lever mixer taps in the kitchen and bathtub and basin The bathroom and kitchen used to have two hole single taps.
• Both in the kitchen and bathroom have pipes with isolation valves Do I need check valves of any kind in the bathroom basin and kitchen or does it seem legit as from what I can see I just have isolation valves which turn off the water.

• When I run the fountain mixer taps in basin and bathtub, when touched one side of water running is cold and the other hot, do I have the right taps for the system as the kitchen tap has a single lever round tap and when I touch the water both sides are balanced e.g warm or hot water and their is no hot side or cold side to the water.

• Do I need check valves of any kind in the bathroom basin and kitchen or does it seem legit as from what I can see I just have isolation valves which turn off the water.

The kitchen hot pipe feed under sink has a check valve and the basin isolation valves I think, see pics.

Any information to steer me in the right direction would be great thank you all

 

[ianmcd]

hot water is less pressurised (hot feed is via a tank in the attic shared by all those who live in the building)

Not with a combi it isnt

 

[CBW]

If you do indeed have a combi boiler, then check valves are not normally required.