unvented hot water cylinder in a roof space of a two storey house

[Benny2513]

unvented hot water cylinder in a roof space of a two storey house in an existing property what is best option for discharge pipe to terminate.It will be 22mm copper but didn't want to run it all the way down the back of the house to ground level if possible.

 

[Ben-gee]

You must be G3 to do this, in which case you’d know how to terminate- also work out size of discharge pipe.