Zilmet CAL-PRO 250 Litre Expansion Vessel

The Expansion Vessel must be fitted to the Return Side of the Central Heating System and in such a way that there can at no time be an obstruction between the vessel and the system. The orientation of the expansion vessels Water Connection should be downwards to avoid risk of sediment ingress or other debris from the system. Some provision for the prevention of air ingress into the vessel must also be made as this will degrade the vessel very quickly.