Since 1996 EROS 2 has surveyed 440 square degrees at high Galactic latitude in order to search for high proper motion stars in the Solar neighbourhood. We present here the analysis of 250 square degrees for which we have three years of data. No object with halo-like kinematics has been detected. Using a detailed Monte-Carlo simulation of the observations, we calculate our detection efficiency for this kind of object and place constraints on their contribution to various halo models. If 14 Gyr old, the halo cannot be made of more than 18% of hydrogen white dwarfs (95% C.L.).