Topotactic reduction of YMnO3 with CaH2 yields three new reduced phases. Two of these phases appear to have compositions close to YMnO2.5 but with very different anion vacancy ordering. The third phase has a composition of YMnO2.33, suggesting it is either the first topotactically reduced phase containing Mn(I) or that YMnO2.33Hx the first complex manganese oxide-hydride has been formed. We propose to investigate the nuclear structures and magnetic ordering present in these new phases by neutron powder diffraction.