in that case make doubly sure you dont run the pump dry when you refill the loop. it will kill the pump. unplug the psu from the wall and hold down the power button for a few seconds. also be sure to clean up any spills with a dry cloth then wipe the area down with 90% isopropyl alcohol. if you have a big spill disconnect everything connected to the part thats wet and literally douse it with alcohol until you have flushed any and all water out. shake out as much alcohol as you can then leave it standing on end(which ever looks like it will allow it to drain out the best) overnight. check it in the morning. use compressed air to blow it out. make sure there isnt any leftover alcohol or water sitting in it. if completely dry hook it back up and your gtg.
never try to power on the rig if you arent 100% sure that any spills arent completely dry.
if you post up some pics of his loop we can help you figure out the best way to drain and fill it.