if you want the gravity to work 100%, rerun the pipe so the flow and return rise to ceiling closer to stove, say from boiler tapping to out side of wall then rise up to ceiling. Inside floorboard void, where the pipes run from cylinder to where it drop down to stove, it must have a fall of 2 inchs to every metre toward where it drop down. The gravity pipe flow is to have a open vent fitted.
I have used this way many time with parkray.
Otherthing, is the cylinder vented?
Dan.
I have used this way many time with parkray.
Otherthing, is the cylinder vented?
Dan.