Home Water Heating Expansion Vessel with Check Valve Expansion Vessel with Check Valve This DXUKIT1 Expansion Vessel is for use with unvented systems where hot water expansion cannot be accommodated in the pipework. Expansion vessel with check valve 2 Litre vessel set at 3.5 bar SKU: DXUKIT1 Category: Water Heating Related products 3.5kW/5.5kW Delux Digital Inline Water Heater Read more 7.5kW Delux Digital Inline Water Heater Read more 2kW Delux Digital Unvented Water Heater Read more Vented Mono Block Mixer Tap Read more