Heat exchanger system (14) through which a liquid is intended to flow, comprising a heat exchanger (4) with a liquid inlet (4a) and a liquid outlet (4b), a bypass valve (6) with a liquid inlet and a liquid outlet, and a self-cleaning filter (2) with a liquid inlet (2a) and two liquid outlets, one being an outlet (2b) for filtered liquid and one being an outlet (2c) for non-filtered liquid, said outlet for filtered liquid being connected to the inlet of the exchanger and said outlet for non-filtered liquid being connected to the inlet of the valve, the liquid outlet of the exchanger being connected downstream of the outlet of the valve. Fuel circuit (10) for an aircraft jet engine comprising such a system.