Alpha Expansion Vessel 8 Litres 1.039208/IM

The Alpha expansion vessel is an 8 litre sealed diaphragm vessel used in the heating circuit of Alpha domestic boilers. Its internal diaphragm separates the pressurised air charge from the system water, allowing the water to expand as it heats without an excessive rise in system pressure. The vessel is listed against the Alpha Eco2, E-Tec, Evoke and Intec boiler ranges and carries the manufacturer part number 1.039208/IM.

• System pressure climbs significantly as the boiler heats up and drops again when it cools.
• The boiler loses pressure repeatedly and needs frequent topping up.
• Water, rather than air, escapes when the charge valve on the vessel is depressed.
• The pressure relief valve discharges during normal heating cycles.
• The boiler locks out or displays a low pressure fault that cannot be held after refilling.

• Match the part number stamped on the existing vessel against 1.039208/IM to confirm the correct unit.
• Check the appliance serial and GC number against the compatibility list, as the same range can use more than one vessel size.
• Older listings and parts catalogues may quote the alternative numbers 1258754 or 039285 for the same item.
• Inspect the vessel connection and its seal at the same time, since the joint is disturbed when the vessel is removed.