The title hydrated salt, C₃₀H₂₆N₆²⁺·2C₉H₅N₄O⁻·3H₂O, was obtained as an unexpected product from the hydrothermal reaction between potassium 1,1,3,3-tetracyano-2-ethoxypropenide, 4,4′-bipyridine and iron(II) sulfate heptahydrate. The cation lies across a twofold rotation axis in the space groupI2/awith the other components all in general positions. In the cation, the H atom linking the pyridine units is disordered over two adjacent sites having occupancies of 0.66 (4) and 0.36 (4),i.e.as N—H...N and N...H—N. The water molecules of crystallization are each disordered over two sets of atomic sites, having occupancies of 0.522 (6) and 0.478 (6) for one, and 0.34 (3) and 0.16 (3) for the other, and it was not possible to reliably locate the H atoms associated with these partial-occupancy sites. In the crystal, four independent C—H...N hydrogen bonds link the ionic components into a three-dimensional network.