hi, this is the 2nd time my rear water washer has packed up on me. two consequtive years.

is it to do with the cold weather causing the pipe to burst off of the pump?

Cheers,

Yes. Putting more-concentrated washer fluid in will help, although IME it doesn't always mix well so can still freeze in the pipes if weaker stuff's already in there. If you don't know how to fix it yourself, the info is here:

http://briskoda.net/forums/topic/93030-rear-washer-jet-issues-help/page__view__findpost__p__1150674