Hot Water tank has 5 pipes

[Wet5park]

What's the 5th pipe for which is connected to the Hot water tank?

1. Top of Tank - Hot water for house/ vent
2. Top/Middle - from boiler
3. Middle/ Bottom - return to boiler
4. Middle / bottom - Unknown warm pipe 22mm
5. Bottom - cold feed from loft storage.

I was expecting 4 pipes.
Thanks[/b]

 

[lightning]

secondary return or essex flange going to shower

Thanks Paul

 

[Wet5park]

Thanks Paul,

Now to work out where the pipes run to/ from and hopefully avoid lifting a tiled floor.

I'm also now clued up on Essex Flange's. Thanks again