Most solar pumping systems are based on photovoltaic receivers driving electric pumps. An alternative system is to use a boiling water solar receiver to operate a direct acting steam pump. The advantages lie in the relative simplicity of the pump giving ease of manufacture, maintenance, reliability and low cost. At De Montfort University a simple direct acting steam pump has been developed over many years, so it has been a natural development to link this with a boiling water solar receiver. This paper is primarily concerned with the operation of the pump and overall system employed.