$$\nonumber 
  \sin^2\theta_W = 0.2252~ \pm 0.0011 \,{\rm {\scriptstyle{(experimental/fit)}}}~ 
                             ^{+0.0003}_{-0.0001} \,{\rm {\scriptstyle{(model)}}} 
                           ~ ^{+0.0007}_{-0.0001} \,{\rm {\scriptstyle{(parameterisation)}}}~.$$

The world average in PDG14 for the on-shell value is $\sin^2\theta_W = 0.22333~ \pm 0.00011 {\rm (total)}$. The measurement presented here is slightly high in comparison to the world average. The precision of this result is comparable to the experimental precision achieved in the neutrino sector [@NuTeV; @PDG14]. The advantage of the present extraction is that the nuclear effects that have to be taken into account in the analysis of neutrino heavy-target data are not present in $ep$ data. A cross-check was performed with the PDF parameters fixed to ZEUS-EW-13p. The result is $\sin^2\theta_W = 0.2241~ \pm 0.0009\,{\rm {(experimental/fit)}}$, which is compatible with the result from ZEUS-EW-S.

The three mechanisms as listed above influence the result to different degrees. The first mechanism exploits the NC data. The influence of the second mechanism was tested by fixing $G_F$ to its PDG14 value in Eqs. \[eqn:xsec\_CC1\] and \[eqn:xsec\_CC2\]. This removed the influence of the CC data and resulted in an increase of the experimental/fit uncertainty by a factor of three. This demonstrates that both NC and CC data contribute significantly to the full precision. The influence of 