Sime DHW Expansion Vessel 8 Litre 6245108

The DHW expansion vessel 8 litre is a diaphragm vessel manufactured by Sime for use in the domestic hot water circuit of compatible Sime appliances. It absorbs the volume increase in heated domestic water, limiting pressure rise at the tap and protecting the appliance's hydraulic components. The part is identified by Sime part number 6245108.

• Water discharging from the vessel's air valve or Schrader valve when the charge is checked
• Pressure in the DHW circuit rising rapidly during heat-up, with relief discharge at the pressure relief valve
• Visible corrosion, blistering or water staining on the vessel shell
• Loss of air charge that will not hold after recharging to the specified pre-charge pressure
• Tapping the vessel gives a solid, water-filled note across the whole body rather than a hollow ring

• Confirm the appliance model and serial number against the fit list above
• Check the part number stamped or labelled on the existing vessel is 6245108
• Verify the vessel volume and connection arrangement match the failed unit before removal
• Isolate the DHW supply and depressurise the appliance before dismantling