F-05 is a blockage in the pump.
At the front of the machine there is a plastic panel along the bottom. Pull this downwards and the cover will drop forwards, you then lift the three bottom clips and the panel lifts clear.
At the right hand side is the seal into the pump chamber.
***Switch off the electrical power supply to the machine***
Drain as much water as possible from the drum, after the door lock has released. Some water in the bottom of the tank and in the pump will run out when you open the pump chamber, so make sure you have something to collect it and mop up.Turn the pump cover several turns anti-clockwise to release, this then simply pulls out, gently wash and clean the rubber seals, do not scrape the seals or they will leak after refitting.
You will see 4 paddles which form the blades of the pump they should turn freely, remove any materials or debris you find in the pump chamber and check that there is no obstruction in the hose feeding into the pump.
Refitting the cover is the reverse of removal, gently push the cover into place and turn clockwise for several turns until tight, the cover should turn easily, do not force as you could damage the plastic thread.
Switch on the machine and set to "drain" only (2:00 minutes) and you should be able to here the pump turning.
There may be more debris in the drum, hoses, or pump so you should check the pump chamber again after you have washed another load.
Refit the bottom front panel in the reverse order to removal once you are sure that the pump is draining correctly
Indesit in their instruction manual recommend that you check this occasionally to prevent a build up of debris.
me, February 2008