The hydriding behavior of the heavy fermion compound UNiA1 has been investigated. A range of hydride compositions with orthorhombic structure (space group Pnma) has been stabilized. As a result, a different nomenclature for the UNiAlHy hydride phases is proposed. X-ray diffraction and magnetic studies are reported on three compositions in this range of hydrides, viz., y = 0.06, 0.14, and 0.58. All these compositions do not show magnetic ordering down to 2 K, though weak ferromagnetic correlations are apparent in their magnetic studies. Low effective moment values on uranium atoms in these cases, appreciably below the value for itinerant antiferromagnetic UNiAl, indicate increased itinerant character of U 5f electrons. We also report magnetization studies on hexagonal UNiA1Hy (y = 0.7). It shows ferromagnetic ordering below 87 K. This means that in the hexagonal hydride phases, the nature of magnetic ordering changes from antiferromagnetic (y = 0) to ferromagnetic (y = 0.7) and again back to antiferromagnetic for y = 2.3. It is shown that the moment on the uranium atoms in the hexagonal hydride phases (y≅0.7 and 2.0-2.5) is close to the free-ion local moment value.