One pipe circulation

[Johnyc86]

Hi just wondering does a presurised hot cylinder outlet have to be @470mm on the horizontal like with a open vented cylinder??

 

[Knappers]

The principle is the same when it comes to hot water convection so I guess its still a good idea, not sure what the regs say on that one but without the vent in a cold loft it's not much of a issue