Some Gardena resources appear on following page, including Gardena link for parts.
http://waterheatertimer.org/How-to-program-Gardena-C1060.html
Add a comment and say where you were able to buy parts, since others are also asking for parts.
And also say how you were able to repair the water timer.
Upvote the help.
And take advantage of fixya expert assistance live.
For a price, expert works with you while you work on timer or any do-it-yourself project.
Fixya is always less expensive than a service call.