Whats wrong with my Citroen C3?

[The Rat]

You get what you buy and unfortunately any Citroen is a piece of rubbish.

[convert]

Since you say it's not worked since the cold weather it could be that you've blown the fuse, trying to wash the screen when the jets have been frozen.

 

When you press the button can you hear the pump running (usually a buzzing sound)?

 

It could also be that the tube has come off the pump / or jets.