From
another forum ;
Indesit Washing Machines and Washer Dryers
F10 - No cold fill. Check that the taps are on or if the drain hoses are kinked.
F11 - No hot fill.The ambient temperature is likely to be below freezing possibly due to the pipes being frozen. Also check that the taps are on or if the drain hoses are kinked.
F12 - No mixed fill. It is likely that the water is not turned on at the taps.
F13 - Check the water supply, inlet valve and hot and cold hose connections.
F14 - A fault with the water heating has occurred. Book a service engineer
F15 - Water is not being pumped out and a flood condition could occur. Check that the drainage hose is raised to the recommended minimum height and that the pipe is not blocked.
F16 - Extremely high water level Disconnect or turn off the water supply and ensure that the water level does not rise any more. Then Book a service engineer.
F17 - Door not closed properly. Close door firmly at the 3 o'clock position.
F20/1 - The thermistor resistance has drifted or the temperature scanning sequence is incorrect. The ambient temperature could be below freezing. Book a service engineer.
F30/31 - A motor drive problem has occurred. Try running the programme again. If the problem persists book a service engineer.
F40 - Water below protection level during a heat step. Book a service engineer.
F41 - Water level detect sequence incorrect. Book a service engineer.
F50/51 - Customer language and wash programme have not been saved. The system will run with default conditions Now having the complete error code list, the DENO does not come up with a code, may be a fatal error
I believe Indesit and hotpoint are basically the same.