Identifying mains water supply from other pipes?

[loffler]

Is there an easy way to tell which is the mains pipe feeding the cold water tank other than working back from the tank itself. (which is very difficult in my house!)

I am wanting to install an electric shower on the mains riser, but there are about 6 copper pipes in the area that I want to splice into and don't want to cut the wrong one!

Thanks

 

[clf-gas]

Your best bet would be to trace back, may be difficult as you say, but thats how we do it. Not enough to say feel which is coldest as this can often be wrong. Put in the leg work now and save regrets later.

 

[2face]

run the hot tap .. it will the fill the domestic tank in the roof there fore the cold main will get colder as u run it .. also usually slightly blacker in colour no idea y .

 

[doitall]

Run hot tap, and stick one end of screwdriver in ear and the other on the pipe till you hear which one is running.

Top Tip;

The sharp end goes on the pipe

 

[gas4you]

Cold mains will probably be 15mm if that helps eliminate some

 

[BoxBasher]

Cold mains will probably be 15mm if that helps eliminate some

Unless they are 22mm

 

[Softus]

Run the central heating - open the bath hot tap (not the cold) for a few minutes. Eliminate anything that isn't very cold.

Whatever remains will be (1) the cold feed to the cylinder (eliminate by observation), or (2) the cold feed to the heating system (this will be warmer the lower down you feel, and certainly won't be very cold), or (bingo) the rising main.