Zilmet - 12 Litre OEM-PRO Grey Round Flat Heating Expansion Vessel - 13A6001200

The Zilmet OEM-PRO 12-Litre Expansion Vessel is a high-quality, space-saving safety component designed to manage thermal expansion within sealed central heating systems and domestic combi or system boilers. When water is heated, it expands; in a sealed loop, this volume change creates rapid pressure spikes. The OEM-PRO vessel houses a pressurised air cushion that absorbs this fluctuating fluid volume, stabilising internal pressure and preventing the boiler’s 3-bar safety relief valve from lifting or dripping.