Temp rise of condenser circulating water

A change from 7⁰ to 10⁰C cannot cause leaks. The only effect is that the temperature on the other side goes up by some amount. If this is unacceptable, then a more regular maintenance is indicated. Incidentally this can also happen if the rate of the circulating water comes down for any reason. This is the more likely reason if this change was sudden. Scaling leads to a slow fall in performance, not a sudden one.