Designed for 'direct on mains' systems (unvented hot water cylinders and combination boilers) where the incoming mains pressure is greater than 2.5 bar but the flow is insufficient to meet demand. MAINSBOOST vessel systems do not require an electrical supply and operate silently. System cold water storage capacity can be expanded by inter-linking multiple vessels. If the incoming mains water pressure is less than 2.5 bar, a MAINSBOOST Charger pump can be used in conjunction with the MAINSBOOST vessel system to boost pressure.