To date, there is no standardised test available, which assesses the actual performance of a pump for wastewater (especially its clog-resistance) as well as providing references about its efficiency. The developed testing procedure presented in this paper can display the different levels of performance for different pumps. The functionality of the pump, together with its efficiency is aggregated to the Functional Efficiency Index (FEI). The developed testing procedure is validated with two pumps from the field. Both are considered to be very prone to clogging by their respective wastewater network operators.