Ideal Potable Expansion Vessel 35 Litres 176754

The Ideal 176754 is a potable expansion vessel with a 35 litre capacity, produced by Ideal for its commercial and thermal store appliance ranges. It provides the air cushion that absorbs the expansion of heated domestic hot water inside a sealed system, keeping operating pressure stable as the water volume increases. The vessel is a serviceable component: once the internal diaphragm fails, the air charge is lost and the appliance can no longer control pressure.

• System pressure climbs quickly as the appliance heats up and falls again once it cools.
• The pressure relief valve discharges water during normal heating cycles.
• The vessel feels heavy or sounds full of water when tapped, indicating a failed diaphragm.
• Frequent manual top-ups are needed to hold the correct system pressure.
• Corrosion or weeping at the vessel connection or mounting point.

• Confirm the appliance model and serial number against the compatibility list before ordering.
• Check that the existing vessel's capacity and connection size match this 35 litre unit.
• Inspect the connection seal or gasket and renew it if it is compressed or perished.
• This is a potable water vessel for the domestic hot water side of the appliance, not a heating circuit expansion vessel.