Problems with Reserator 2

[rcs8]

New build and a newbie for water-cooling.

 

Empty Gigabyte Aurora 570 chassis with Coolermaster 750W PSU.

Reserator 2 with degasser tube installed.

 

Jumped Green to Black on P1.

Plugged in Reserator to wall outlet. Plugged peripheral 4-pin to reserator.

Plugged in PSU and switched on.

 

Reserator powers up after ~1 second, then immediately powers down. Pull jumper out, wait 5 sec, plug jumper back in, Reserator powers up for a second then powers down.

 

What am I doing wrong? Why won't it stay running? The manual is no help.

 

Thanks.