Abstract: The present invention relates to a dishwasher (1) produced without mounting the water softener unit (Y) that is offered for use in places where water hardness is low, but when the water hardness level increases and the water softener unit (Y) is desired to be adapted, only the stopper (10) closing the outlet of the accumulative chamber (6), the lid (11) closing the opening (7) under the tub (2) and the insulations at the electrical connection terminals (8) are removed and the hydraulic, mechanical and electrical connections of the water softener unit (Y) can be easily made by the serviceman.