IKea rengora (whirlpool) not draining problem.

[stringman]

Hi all
we have an ikea rengora dishwasher which came with the house.
recently it tripped its antiflood sensor, I took off the inspection panel a then mopped up the water- job done no more 3 beeps
but now it has the following problem:

it fills up fine but when it should drain (about 5 min into the cycle) it doesn't drain and give one beep repeatedly

if you switch off the machine and reset it it will drain away all the water and then repeat the process again, so the pump and the pipe are fine.

Any ideas?

thanks in advance