Hi all, I've recently had a new heat only boiler on my open vented system,the gravity HW is now pumped and the feed from the F&E tank has been rerouted. There is a capped 22mm in the loft very close to the F&E tank coming from the right direction, could the 22mm vertical pipe on the HW return be the other end? Would that make sense to have the feed there? I'm replacing the cylinder, so will remove this if it's no longer in use. Thanks.