Click to expand Tap to zoom Vaillant 18L Buffer tank for uniTOWER by Vaillant SKU 20269273 Vaillant 18L buffer tank offers the perfect storage solution for your uniTOWER. Its durable design features a high-quality grey finish, making it a perfect match for your boiler. EAN no. 4024074848951. Article no. 336397. Accessories