Alpha Expansion Vessel 8 Litre 1.039285

The Alpha 8 litre expansion vessel is a sealed diaphragm vessel used in the heating circuit of Alpha gas boilers. It absorbs the volume increase of water as the system heats up, holding the circuit pressure steady and protecting components such as the pressure gauge, seals and heat exchanger from unnecessary strain. This vessel is supplied by Alpha and is specified for the Eco 2, Eco 2 Plus and InTEC 2 families.

• System pressure rises quickly when the boiler heats up and falls again once it cools, with the gauge needle swinging across a wide band.
• The boiler loses pressure repeatedly and needs regular topping up, even when no visible leak is present on the pipework or radiators.
• Water discharges from the pressure relief valve during normal heating cycles.
• The vessel feels heavy or water is heard inside it when the Schrader valve is depressed, indicating a failed diaphragm.
• The charge pressure at the vessel valve will not hold when tested with a gauge.

• Confirm the GC number on the appliance data badge against the list above, as several Alpha models share similar casing and vessel layouts.
• Check the existing vessel for the previous part number 1.034098 or the alternative 039285 before ordering, so the correct replacement is selected.
• Inspect the vessel connection and sealing washer on removal and renew the seal if it is compressed or perished.