I have an IDL 700 with the aforementioned 4 lights. Over the past year and a half I have seen the service engineer on 6 separate occasions for various flashing lights. The last time was for the first two and as I had not yet found this page I paid the service engineer (as the unit is now out of warranty to look at it.) The drain pump contained two lemon pips!! I was watching closely and it has recently done it again and I found a sizeable piece of wood.
Procedure - empty all water - incline unit 45 degrees backwards - remove bottom panel - from pump unit remove 1 retaining screw, electical connector (it was a good idea to unplug the unit first) and the rubber hose clamp - turn the pump carefully anticlockwise and remove to a nearby sink to remove whatever the filters have failed to - reassemble. Oh yes you have about a pint of water to clear up. It has now worked for me twice perfectly, however the best advise I saw on this page is don't buy an Indesit.
Steve
March 2005