Horizontal unvented - secondary return

[Scott_D]

Is it true that a horizontal unvented must have a secondary return pump fitted for destratification?
@chris watkins

 

[chris watkins]

Is it true that a horizontal unvented must have a secondary return pump fitted for destratification?
@chris watkins

I don't think they have to but it probably helps to achieve more usable hot water.
You don't actually need a HW return system it might be more suitable to just fit a small circulator between the hot outlet from the cylinder & the cold feed with a suitable check valve. This could be powered from a call for domestic hot water (if it is an indirect) i.e. brown on zone valve, in that way it would be de-stratified only when it is being heated, should lead to a greater volume of usable hot water.

 

[ShaunCorbs]

Yes it’s best to or oversize as you loose around 40% cap