The Powermax P781 18L Expansion Vessel is a genuine replacement pressure vessel designed for use in compatible Powermax heating systems. The vessel absorbs excess pressure created as water expands during the heating cycle, protecting the system from over-pressurisation, leaks, and unnecessary strain on components.

A degraded or waterlogged expansion vessel can cause repeated pressure drops, PRV discharge, noisy operation, or boiler lockouts. Replacing it with this genuine 18-litre Powermax vessel restores correct system pressure regulation and ensures stable, reliable heating performance.

Key Features

• Genuine Powermax 18L expansion vessel

• Maintains stable pressure during heating expansion

• Prevents over-pressurisation and PRV discharge

• Helps resolve pressure faults and system lockouts

• Durable white steel construction

• Direct-fit replacement for straightforward installation

Compatible With

Suitable for selected Powermax boilers and thermal stores requiring expansion vessel P781 (18L).

Please verify compatibility with your system manual or the existing vessel before ordering.