Good day how are you? I wanted to ask you the following: in a dual wall boiler eskabe acquapiu model A23, plugging it in shows me on the display (board) fault E3, in the manual it tells me that it is a problem NTC heating and because of that the boiler does not work. They only use it in a sanitary way since no radiator is connected to the house. I would like to know how the problem could be solved. Thanks a lot.