The people who owned my house before me had the water tank(s) in the attic
disconnected and a combi boiler installed. We now have three pipes capped
halfway up the wall in the 2nd bedroom, which for obvious reasons I want to
remove ! Two of these are obviously hot and cold (15mm) water pipes, one of
which I've removed. The 3rd is a pretty wide pipe (well a lot bigger than
22mm anyway). Does anyone have any idea what it might be ? Would it be gas
? (I'm guessing the boiler used to be in this room)

Also I've noticed the pipe I've not removed is still connected to the mains
(guess how I know that!), is it wise to cap it off under the floorboards, or
would it be better to get it removed from where it joins the main (used?)
piping in the house ?

Thanks

Séan