A liquid delivery system comprising a base unit (2) comprising a liquid inlet in an upwardly facing surface, a liquid duct leading from the inlet to a liquid outlet above the liquid inlet; a pump for pumping the liquid from the inlet to the outlet; a motor to drive the pump; and a shroud extending upwardly in a manner which surrounds the inlet, the shroud having an upper edge which has a downwardly extending recess (20) for a part of its circumference; characterised by the system further comprising an insert (21) in the recess (20) which forms a liquid-tight seal with the recess (20) and defines, with the shroud, a liquid cavity in communication with the liquid inlet in the base.