The Vaillant expansion vessel with a volume of 10 liters is an essential spare part for heating devices, especially for fan heaters. It serves to regulate pressure in heating systems and ensures that the water in the system can expand optimally with temperature changes, preventing pressure spikes. This product is specifically designed for the models VC-W 126-246-/2, VC 136, and 276-E, ensuring reliable functionality. Made in Germany, it stands for quality and durability. The delivery includes an expansion vessel sold as a single unit. Using an appropriate expansion vessel is crucial for the efficiency and safety of heating systems, as it helps maintain stable pressure in the system and thus extends the lifespan of heating devices. This product is a sensible investment for anyone looking to operate their heating system optimally.