Hot Water cylinder expansion pipe

[Steve Tansley]

I recently had a look over the pipe and noticed that the hot water cylinder
expansion pipe has been plumbed in to vent into the main cold water tank in
the loft. Is this normal ?

[Peter Andrews]

Yes - and the CH / boiler expansion pipe vents into the CH header tank (the small one).
Peter

[John]

"Into" or "Over" the tank?

[John Rumm]

Yes

[John Rumm]

Both. ;-) The expansion pipe - as in the "feed and expansion" connects to the header below the waterline. The vent pipe should be looped over the top of the tank such that any water would fall from it into the tank