Glow-worm Expansion Vessel 8 L 0020020744

Genuine Glow-worm expansion vessel for sealed heating systems on selected Glow-worm boilers. This rectangular, red 8-litre vessel cushions pressure increases to protect the boiler and system components.

• Manufacturer: Glow-worm
• Part type: Expansion vessel (sealed system)
• Capacity: 8 litres
• Shape/colour: Rectangular, red
• MPN: 0020020744
• GTIN / EAN: 5037985010989

Compatible ranges

Used across several Glow-worm families including:

• Flexicom (e.g., 18SX, 24CXi, 30CXi, 35CX)
• Ultracom (e.g., 18SXi, 30SXi)
• CXi / SXi series
• Micron (selected FF models)

Note: Model fit varies by production date. Always verify against your boilers data plate or parts manual using the part number above.

What it does

The expansion vessel contains an air charge separated from system water by a membrane. As water heats and expands, the vessel absorbs the volume change, helping to maintain stable system pressure and reduce stress on components.

When to replace

• Frequent pressure loss or pressure rising rapidly on heat-up
• PRV discharging or dripping
• Vessel fails to hold pre-charge (membrane failure)

Installation & Safety

Must be fitted and pre-charged by a qualified, Gas Safe engineer. Incorrect charging or installation can lead to system faults or damage.