z800 Liquid Cooling not boot

I have 2 z800 machines. One is non-functioning and has a MB issue and I ordered a new board from eBay for it, the other machine is working fine. The working one has 2 CPUs and CPU fans. The fans are not as quiet as I would like (though not bad for such a powerful box) so I thought I would try out the recently purchased official HP z800 liquid cooling unit that I had lying around. It was meant to be used with the non-functioning machine.
 
I installed the liquid cooling unit using the directions described here,
http://h20564.www2.hp.com/hpsc/doc/public/display?docId=emr_na-c01829154
 
Plugged everything in and turned the machine on. The fans (except RAM fans) started quietly, but no boot into bios. Then about 10-15 seconds later the fans started going very hard (RAM fans never ran). The machine would not boot.
 
So I took the liquid cooling unit out and put back the old fans. Rebooted the box and everything was back to normal.
 
So the question is what are the issues to look at when the liquid cooling unit cause a failure to boot?