An expansion vessel is a device that takes up the expansion of water in the domestic hot water system when it is heated. This prevents build up of excess pressure. The non-return valve prevents backflow of expanded hot water in to the cold water main.
Ariston – Europrisma 2 Litre Water Heater Expansion Vessel & 15mm Check Valve Kit A Alternative
Compatible with: Ariston Europrisma and Ariston Andris Under or Oversink 10Ltr, 15Ltr, & 30Ltr