Vaillant Expansion Vessel 181051 (10L)

Genuine Vaillant OEM expansion vessel for sealed heating systems on selected Vaillant boilers. The vessel absorbs water expansion on heat-up to maintain stable system pressure and protect components.

• Manufacturer: Vaillant
• Part type: Expansion vessel (sealed system)
• Capacity: 10 litres
• Form factor: Rectangular
• Connection: 3/8
• MPN: 181051
• GTIN / EAN: 4024074334713

Compatible boilers (examples)

Used widely across ecoTEC Plus/Pro and ecomax models (variant/year dependent). Common fits include:

• ecoTEC Plus 824, 831, 837, 937
• ecoTEC Pro 24, 28
• ecomax selected VU/VUW models

Always verify against your boilers data plate or parts list using MPN 181051.

Dimensions

• Approx. H 435 W 250 D 100 mm
• Supplied with washer (as per many supplier kits)

What this part does

The vessels air charge cushions pressure rises in sealed systems, reducing PRV discharge and protecting the heat exchanger and other components.

When to replace

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

What’s in the box

• 1 Vaillant expansion vessel 181051 (10L, rectangular)

Installation & safety

Must be fitted and pre-charged by a qualified Gas Safe engineer. Set pre-charge to manufacturer guidance and verify system pressure after installation.