Thanks for that,
So you think that the vent required is to solve option b). Air buildup in the highest point.
If that is the case then aavs sound like the way forward.
HI Folks,
Novice question here. I just received my salamander pump and because the pipe run from the pump goes back into the attic and down to the shower they recommend "air vents" on both the hot and cold pipe run.
What I can't work out is if its a vent to get air out, or leave air in...