Equilibration of a DPD run

Hello everyone,

I want to confirm if the DPD run of my system has reached equilibration. Every time I check the energy graph, it seems that the energy of the system is almost constant from the start of the simulation. Then I check the Mean square displacement of the beads and it never plateaus to a constant value. I have attached graphs of the energy and mean square displacement of a system just having water beads at 298 K. I have even tried different mappings but it still doesn't seem to work. What might be the reason for this? Is it the time step, or the value of the dissipation strength (default value used), initial velocities (set to random) or something else? 

Thanks