This paper presents the first results of a study which is being carried out at GRETh about the link between plate heat exchanger configuration, flow maldistribution and particulate fouling propensity in plate heat exchangers equipped with a significant number of plates (121). The following parameters are being studied: geometry of the plate, flowrate, flow arrangement (U and Z). The TRICOT software, developed and experimentally validated at GRETh, allows the prediction of the flow distribution between the plates. Then by testing the industrial heat exchanger on a semi-industrial test rig under controlled fouling conditions, flowrates and temperatures at the inlet, the temporal evolution of the fouling resistance is measured. Pressure measurements at the outlet of some selected channels provide more informations about the consequences of the maldistribution on fouling. We propose to use the relative pressure loss evolution measured in these channels as a fouling indicator. Its variation can explain why the straightforward results obtained in previous experiments in simple channel have to be relativized.