A system and method for verifying the operational condition of a rectangular baler having a baling chamber equipped with a reciprocating plunger, the plunger moving between a fully retracted position and extended position, the baler further equipped with a load sensor suitable for determining the reaction force on the plunger as said plunger is compressing crops. Verifying the operational condition includes measuring the reaction force on the plunger or a parameter related to said reaction force, when the plunger is in a position in which it is not exerting a compressive force on the crop material in the baling chamber, comparing the measured reaction force or the parameter to a predefined reference value, and deriving from that comparison an assessment of the baler's condition