Solid ice on coils

Question

On one of my delonghi PACL90 models, there is a solid sheet of ice forming on the coils between them and the filter. I had it turned off and melted it with a hairdryer, drained it by openning the two drain tubes at the bottom, waited 12-14 hours and then tunred it on again only to have the ice form again. Is the unit gone or is there a solution?