H110 pump on Maximus VII Hero headers

Hello everybody. I'm confused about how to set up the H110 on my Maximus VII Hero. I put the pump into the CPU_Fan header, one of the H110 fans into the CPU_OPT, and the other fan into a chassis fan header. How do i know my pump is working properly? The CPU_OPT fan seems to run at a constant 750RPM I use Fan Xpert 3 to make the fans work their hardest or the system starts heating up. I just want to make sure my pump is working at max speed because I was able to overclock my i4790k from 40 to 48, but it started crashing and blue screening randomly while playing games (I haven't overclocked the GPU yet).