The Baxi 240388 is a genuine OEM expansion tank (expansion vessel) designed for selected Baxi, Main, and Potterton heating appliances. This pressurised tank absorbs the natural expansion of water as it heats, stabilising system pressure and protecting internal components from over-pressurisation.

A failing or waterlogged expansion tank can lead to pressure spikes, frequent pressure loss, PRV discharge, boiler lockouts, or the need for constant top-ups. Installing this genuine Baxi component restores correct system pressure management and reliable operation.

Key Features:

• Genuine Baxi expansion tank

• Maintains stable system pressure by absorbing water expansion

• Prevents PRV discharge, pressure spikes & lockouts

• Essential for efficient and safe sealed system operation

• Built to Baxi’s strict OEM standards for performance and durability

• Ideal replacement for failing or saturated vessels

• Direct-fit installation for fast, reliable servicing

Compatibility

The Baxi 240388 Expansion Tank is compatible with:

• Baxi boilers

• Main boilers

• Potterton boilers

• Any appliance listing 240388 in the official parts documentation

Common compatible ranges include older and legacy models, such as:

• Baxi Solo

• Potterton Profile

• Main System and Heat appliances

(Exact compatibility varies—installers must confirm via the service manual.)