It did this last week and I figured the crappy stock fluid froze and sure enough it was working a couple days later when I tried it. Well it's fairly warm, 16F out tonight and it pumps but no fluid sprays out of either front nozzle or the rear and the fluid is not frozen in the tank.
Liked said, I can hear it pump when you try but nothing. Just like frozen fluid.
Guess I have to take it in under warranty.