rear washer jet

I have an issue with the rear washer jet.

Of a morning it is dry. Over a 20 mile journey to work I have a very small drip which runs down the rear screen. It is only a very small amount of 'water' but it marks the rear screen.

It's been happening over the last two or three weeks. It only happens when I drive, and I think it was after I filled the washer bottle to the top. Could this be the reason?

If it needs repair how easy is it. It's in the top brake light

Theres a thread on this somewhere,it's happened to a few people,can't remember what the fix was as it was some time ago but it was fixable

Car pack from the dealer - all repaired under the warranty. Seems that it's a common issue as we have a hard water area.

Never thought about using soft water from our water conditioner before - I thought the windscreen solutions contained softening agents!