Indesit WD12UK continuous filling?

Indesit WD12UK continually fills with water on all cycles including spin and drain. The machine does not overflow but never stops letting in water even during draining. The pressure bottle, pipe and sump hose have all been cleaned and checked (there were pennies in the sump hose) and the pressure switch clicks when blown intoproviding continuity between two of the terminals.
Is this likely to be a faulty pressure switch or the electronic control module or ay other suggestion?