A control system may include a recirculation circuit configured to direct fluid from an outlet of a fluid pump of a hydraulic fracturing system to an inlet of the fluid pump. The control system may include a control valve in the recirculation circuit. The control system may include a controller configured to cause opening of the control valve to cause the fluid to flow through the recirculation circuit at a first time when proppant is being added to the fluid. The controller may be configured to cause, after closing of the control valve and at a second time when the proppant is no longer being added to the fluid, re-opening of the control valve to cause the fluid to flow through the recirculation circuit to flush the recirculation circuit of the proppant.