Grant Expansion Vessel 12Ltr Combi Replaces 10Ltr Mpss01

Hook on Back Euroflame Internal 50/90 90/12 COMBI MK2 & V3 Vortex ECO Vtx Combi 26 pre Dec 2014 Vtx 15/26 post Aug 2008

Grant Expansion Vessel 12Ltr – MPSS01

Replaces 10Ltr Vessel in Grant Combi Boilers | Genuine Part for Reliable Pressure Management

Maintain safe and stable boiler pressure with the Grant MPSS01 Expansion Vessel, a 12-litre replacement unit designed for use in Grant Combi boilers. This high-quality, genuine Grant part replaces the previous 10-litre model and ensures your sealed heating system can accommodate thermal expansion effectively, reducing the risk of pressure-related faults and leaks.

Ideal for heating engineers conducting boiler repairs or servicing, and suitable for confident DIY homeowners, this vessel is an essential part for any sealed Grant system operating efficiently.

Key Features & Benefits

• Genuine Grant Part – MPSS01
  Official manufacturer replacement for total compatibility and long-lasting performance.

• Increased Capacity (12L)
  Replaces the older 10-litre model for improved pressure buffering in modern combi systems.

• Controls Pressure Fluctuations
  Absorbs expansion of heated water, preventing overpressure and system strain.

• Robust Steel Construction
  Built to withstand high temperatures and pressure cycles in sealed central heating systems.

• Compact, Boiler-Integrated Design
  Designed specifically for combi boilers—space-saving and easy to fit within the unit.

 Compatible Grant Boiler Models

The MPSS01 12Ltr Expansion Vessel is used in various Grant Vortex Combi models, including:

• Grant Vortex 21kW Combi

• Grant Vortex 26kW Combi

• Grant Vortex 36kW Combi

If you're unsure whether this vessel suits your boiler model, contact our expert support team—we’ll help you find the correct part.

 

 When to Replace the Expansion Vessel

Replace the expansion vessel if:

• The system pressure rises too quickly or triggers the pressure relief valve

• You notice water leaking from the pressure relief discharge pipe

• The existing vessel is corroded, ruptured, or cannot maintain charge

• You’re carrying out major boiler servicing or replacing related pressure components

A faulty expansion vessel can lead to erratic pressure, leaks, or even boiler shutdowns—don’t delay a replacement.

 

 

 Technical Specifications

• Part Number: MPSS01

• Manufacturer: Grant UK

• Type: Internal expansion vessel for combi boilers

• Capacity: 12 litres (replaces 10-litre version)

• Pre-Charge Pressure: Typically 0.75 – 1.0 bar (check boiler manual)

• Mounting: Internal boiler casing

• Material: Powder-coated steel with internal diaphragm

Used in heating systems. Helps to manage the changes in volume of the heating medium as it heats up and cools down. This vessel maintains system pressure, preventing excessive pressure fluctuations and ensuring the efficient and safe operation of the heating system. With a larger capacity, it's suitable for systems with higher heating demands.

Suitable with:

GRANT

• COMBI 70 MK II

• COMBI 70 V3

• COMBI 90 MK II

• COMBI 90 V3

• COMBI MAX

• EUROFLAME 90-120 OUTDOOR

• EUROFLAME 90-120HOUSE

• EUROFLAME KITCHEN/UTILITY 90-120

• EUROFLAME OUTDOOR MODULE 50-70

• EUROFLAME SYSTEM 90-120

• MULTIPASS KITCHEN 110-140

• MULTIPASS KITCHEN 140-160

• MULTIPASS KITCHEN 160-200

• MULTIPASS KITCHEN 50-70

• MULTIPASS KITCHEN 70-90

• MULTIPASS KITCHEN 90-110

• MULTIPASS KITCHEN 90-140

• MULTIPASS OUTDOOR 110-140

• MULTIPASS OUTDOOR 140-160

• MULTIPASS OUTDOOR 160-200

• MULTIPASS OUTDOOR 50-70

• MULTIPASS OUTDOOR 70-90

• MULTIPASS OUTDOOR 90-110

• MULTIPASS OUTDOOR 90-140

• MULTIPASSHOUSE 110-140

• MULTIPASSHOUSE 140-160

• MULTIPASSHOUSE 160-200

• MULTIPASSHOUSE 50-70

• MULTIPASSHOUSE 70-90

• MULTIPASSHOUSE 90-110

• MULTIPASSHOUSE 90-140

• OUTDOOR COMBI 90 MKII

• VORTEX ECO EXTERNAL 15-21 CONDENSING

• VORTEX ECO EXTERNAL 21-26 CONDENSING

• VORTEX ECO EXTERNAL 26-35 CONDENSING

• VORTEX ECO UTILITY 15-21 CONDENSING

• VORTEX ECO UTILITY 21-26 CONDENSING

• VORTEX ECO UTILITY 26-35 CONDENSING

• VORTEX PROEXTERNAL 26E COMBI CONDENSING

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