Baxi Expansion Vessel Primary 12L 95607066

The Baxi 95607066 is a primary expansion vessel with a 12 litre capacity, manufactured by Baxi for use in its domestic heating appliances. It absorbs the volume increase of the system water as it heats, holding the circuit pressure within safe working limits and protecting components such as the heat exchanger and pressure relief valve from unnecessary strain. This vessel is the primary type, fitted to the appliance's main heating circuit rather than a separate domestic hot water store.

• System pressure drops repeatedly and needs topping up, with no visible leak on the pipework or radiators.
• The pressure gauge swings widely between cold and hot states, suggesting the vessel can no longer absorb expansion.
• Water discharges from the pressure relief valve during heating, often leaving a trail from the discharge pipe.
• Water is present at the vessel's air valve or the schrader connection when the cap is removed.
• The vessel feels heavy or full of water when tapped, or the charge pressure will not hold when tested.

• Confirm the appliance model and serial number against the compatibility list, as Baxi used more than one vessel across its ranges.
• Check the part number on the existing vessel or in the appliance's installation and service documentation before ordering.
• Inspect the vessel connection and any sealing washer or O-ring at the same time, as these are often disturbed during removal.