How to adjust heating & water controls Vaillant ecoTECpro?

Since being serviced recently both water & heating have become too hot; the dialls on the left which control water and heating (with plus and minus schemes) must have been altered by the servicer because the indicators are now pointing to the right away from the plus/minus schemes. I do not have an operating manual to consult. Should the diall indicators be turned back to the black plus/minus area to correct the heating & water levels?