Zilmet-Winkelmann Flat Expansion Vessel, 10 Litre

Description

The purpose of an expansion vessel is to protect closed water heating systems and domestic hot water systems from excessive pressure. The tank is partially filled with air which will, when sized correctly, absorbs excess water pressure caused by thermal expansion.

The expansion vessel pressure should be checked each year with the annual boiler service.

It is common if the vessel pressure has dropped that the pressure relief valve on the heating system will begin to pass water.