Machine starts up & works ok for 20 mins,then stops,starts beeping & flashes up -20 fault code.Suggests a drain fault,however there appears to be no drainage problem?
Pcb?
It means that the empty level position has not been achieved inside the time allowed.
Appliance takes 1 & 1/2 minutes from pump start to empty completely, if its not recognised as been empty in this time it will throw up an I20 fault code.
Look for blockage in filters, drain hose, pressure switch hose etc.