whirlpool ADP 4400 7flash fault

Hi all,
I have a whirlpool adp4400 dishwasher, age unknown – I inherited it with my rented house. it has always been a bit up and down on wash quality and stopping and starting – but has performed its basic dishwashing tasks ok.

the function buttons are quite simple, a push on/off button, a dial with 4 programmes on it, a start button with green led above it and 2 red leds one for salt and the other for rinse aid.

last week the green led was flashing and red leds were on so i put in salt and rinse aid, it performed 1 wash ok, then 2nd wash didn’t finish properly and green led was just flashing 7 times.

I have checked through this forum (for hours and hours as i have quite a slow pc) and cannot find what 7 flashes means, and have also cleaned filters, checked inlet and outlet hoses etc.
By keeping my finger on the start button i can force it to start up again – I can clearly hear water going in (so deduce that water inlet valve although unchecked is working ok) and then water going out this lasts for about a minute then it stops – either with all lights off or just the green led flashing 7 times again.

I have chucked in a few kettles full of boiling water to hopefully shift any grease blockages – and there is still no change. this water is emptied away fine when I force it to start up.

As I am moving out of the house in 6 weeks time, and unsure if i am able to take dishwasher with me or not I am loathe to call out an engineer if it is something simple i might be able to fix myself.

all advice gratefully rec’d

CAZ