Whirlpool ADP4554: 4 flashing before draining

[desmo75ts]

Hi guys,
i have this dishwasher since 2003, not any problem for over 7 years
Now the machine has a problem.
It starts without any problem, but before draining it start to flash four times with prewash led on (it doesn't depend from the selected program) and the dishwasher stops.
Holding the start button the final draining takes place and the program will finish.
Where is the problem?
Thanks in advance!
Dario

 

[zipper]

This model is only sold in Italy...however F4 indicates a drain/drain timeout issue regardless of where it is produced/sold. Typical causes of an F4 error include; a blocked/kinked drain hose, blocked/defective drain pump, blocked filters, blocked siphon outlet, or clogged inlet filters. If the machine won't drain on a normal wash cycle...but will drain when you reset it then my first suspicion would be this component http://www.espares.co.uk/parts?k=481227128407. The pressure switch is fitted in the right hand side of the sump. Often they get clogged & don't switch correctly which can result in the symptoms you describe. Make sure the grill isn't clogged & it switches ok. If necessary change it out. The part number in the above link is valid in Italy, any Whirlpool spares stockist should be able to supply this part.