Your spray chamber should read at the cool set point, in this case 2 C, if it is not, there could be a problem with the lower block of the spray chamber. The spray chamber does use cooling water, but also has a peltier cooling block that cools the block.
The chiller should be set to 20C, when they ship from the manufacturer, their default is 15C. You should adjust the temp up.
Thanks for the information James.